diff --git a/backend-java/src/main/java/com/nanri/aiimage/config/SchedulingConfig.java b/backend-java/src/main/java/com/nanri/aiimage/config/SchedulingConfig.java
index 8ce636e8..0d96983f 100644
--- a/backend-java/src/main/java/com/nanri/aiimage/config/SchedulingConfig.java
+++ b/backend-java/src/main/java/com/nanri/aiimage/config/SchedulingConfig.java
@@ -1,6 +1,7 @@
 package com.nanri.aiimage.config;
 
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -20,9 +21,9 @@ public class SchedulingConfig {
     private static final ZoneId BUSINESS_ZONE = ZoneId.of("Asia/Shanghai");
 
     @Bean
-    public TaskScheduler taskScheduler() {
+    public TaskScheduler taskScheduler(@Value("${aiimage.scheduling.pool-size:4}") int poolSize) {
         ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
-        scheduler.setPoolSize(4);
+        scheduler.setPoolSize(Math.max(1, poolSize));
         scheduler.setThreadNamePrefix("aiimage-scheduling-");
         scheduler.setClock(Clock.system(BUSINESS_ZONE));
         scheduler.setWaitForTasksToCompleteOnShutdown(true);
diff --git a/backend-java/src/main/java/com/nanri/aiimage/config/TaskFileJobConfig.java b/backend-java/src/main/java/com/nanri/aiimage/config/TaskFileJobConfig.java
index f56fca1d..f8736d7f 100644
--- a/backend-java/src/main/java/com/nanri/aiimage/config/TaskFileJobConfig.java
+++ b/backend-java/src/main/java/com/nanri/aiimage/config/TaskFileJobConfig.java
@@ -42,19 +42,24 @@ public class TaskFileJobConfig {
             ExecutorService cozeVirtualThreadExecutor,
             @Value("${aiimage.coze-task.max-concurrent:12}") int maxConcurrent) {
         Semaphore semaphore = new Semaphore(Math.max(1, maxConcurrent));
-        return new ConcurrentTaskExecutor(command -> cozeVirtualThreadExecutor.execute(() -> {
-            boolean acquired = false;
-            try {
-                semaphore.acquire();
-                acquired = true;
-                command.run();
-            } catch (InterruptedException ex) {
-                Thread.currentThread().interrupt();
-            } finally {
-                if (acquired) {
-                    semaphore.release();
-                }
+        return new ConcurrentTaskExecutor(command -> {
+            if (command == null) {
+                throw new IllegalArgumentException("coze 任务不能为 null");
             }
-        }));
+            cozeVirtualThreadExecutor.execute(() -> {
+                boolean acquired = false;
+                try {
+                    semaphore.acquire();
+                    acquired = true;
+                    command.run();
+                } catch (InterruptedException ex) {
+                    Thread.currentThread().interrupt();
+                } finally {
+                    if (acquired) {
+                        semaphore.release();
+                    }
+                }
+            });
+        });
     }
 }
diff --git a/backend-java/src/test/java/com/nanri/aiimage/config/ThreadPoolIsolationConfigTest.java b/backend-java/src/test/java/com/nanri/aiimage/config/ThreadPoolIsolationConfigTest.java
new file mode 100644
index 00000000..73ce8636
--- /dev/null
+++ b/backend-java/src/test/java/com/nanri/aiimage/config/ThreadPoolIsolationConfigTest.java
@@ -0,0 +1,249 @@
+package com.nanri.aiimage.config;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.core.task.TaskRejectedException;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
+
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Task 74：隔离调度线程池、文件作业线程池和外部 Coze/图片执行池。
+ * 三个执行池各自独立配置、独立命名、容量互不影响：调度池
+ * （aiimage.scheduling.pool-size，默认 4）与文件作业派发池
+ * （aiimage.result-file-job.*，默认 2 线程/队列 200）互不共享线程；
+ * 外部 Coze 池以虚拟线程 + 信号量限流（默认 12）。容量非法值统一
+ * 钳制到最小值；任务失败后信号量名额与调度槽位必须释放，任一池打满
+ * 不影响其他池。
+ */
+class ThreadPoolIsolationConfigTest {
+
+    private final List<AutoCloseable> closeables = new ArrayList<>();
+
+    @AfterEach
+    void tearDown() throws Exception {
+        for (AutoCloseable closeable : closeables) {
+            closeable.close();
+        }
+    }
+
+    private ThreadPoolTaskScheduler newScheduler(int poolSize) {
+        ThreadPoolTaskScheduler scheduler =
+                (ThreadPoolTaskScheduler) new SchedulingConfig().taskScheduler(poolSize);
+        closeables.add(scheduler::destroy);
+        return scheduler;
+    }
+
+    private ThreadPoolTaskExecutor newDispatch(int poolSize, int queueCapacity) {
+        ThreadPoolTaskExecutor executor = (ThreadPoolTaskExecutor) new TaskFileJobConfig()
+                .taskFileJobDispatchExecutor(poolSize, queueCapacity);
+        closeables.add(executor::destroy);
+        return executor;
+    }
+
+    private ExecutorService newCozeVirtual() {
+        ExecutorService executor = new TaskFileJobConfig().cozeVirtualThreadExecutor();
+        closeables.add(() -> executor.shutdownNow());
+        return executor;
+    }
+
+    private TaskExecutor newCoze(ExecutorService virtualExecutor, int maxConcurrent) {
+        return new TaskFileJobConfig().cozeTaskExecutor(virtualExecutor, maxConcurrent);
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_normal_default_path() throws Exception {
+        // 默认路径：三池按默认容量初始化，正常提交一个任务即可执行。
+        ThreadPoolTaskScheduler scheduler = newScheduler(4);
+        assertEquals(4, scheduler.getScheduledThreadPoolExecutor().getCorePoolSize(), "调度池默认 4 线程");
+        assertTrue(scheduler.getThreadNamePrefix().startsWith("aiimage-scheduling-"),
+                "调度池线程名独立前缀");
+
+        ThreadPoolTaskExecutor dispatch = newDispatch(2, 200);
+        assertEquals(2, dispatch.getCorePoolSize());
+        assertEquals(2, dispatch.getMaxPoolSize(), "文件作业池 core=max，不随压力扩张");
+        assertEquals(200, dispatch.getQueueCapacity());
+
+        ExecutorService cozeVirtual = newCozeVirtual();
+        TaskExecutor coze = newCoze(cozeVirtual, 12);
+        AtomicBoolean ran = new AtomicBoolean(false);
+        CountDownLatch done = new CountDownLatch(1);
+        coze.execute(() -> {
+            ran.set(true);
+            done.countDown();
+        });
+        assertTrue(done.await(5, TimeUnit.SECONDS), "Coze 池默认限流 12，正常提交即执行");
+        assertTrue(ran.get());
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_normal_multiple_items() throws Exception {
+        // 批量场景：三池同时按各自容量配置，各跑一个任务互不阻塞；
+        // 线程名前缀互不相同，线程转储可识别归属池。
+        ThreadPoolTaskScheduler scheduler = newScheduler(6);
+        ThreadPoolTaskExecutor dispatch = newDispatch(3, 500);
+        ExecutorService cozeVirtual = newCozeVirtual();
+        TaskExecutor coze = newCoze(cozeVirtual, 8);
+        assertEquals(6, scheduler.getScheduledThreadPoolExecutor().getCorePoolSize());
+        assertEquals(3, dispatch.getCorePoolSize());
+        assertEquals(500, dispatch.getQueueCapacity());
+
+        CountDownLatch all = new CountDownLatch(3);
+        dispatch.execute(all::countDown);
+        scheduler.schedule((Runnable) all::countDown, new Date(System.currentTimeMillis() + 50));
+        coze.execute(all::countDown);
+        assertTrue(all.await(5, TimeUnit.SECONDS), "三个池同时执行互不阻塞");
+
+        assertNotEquals(scheduler.getThreadNamePrefix(), dispatch.getThreadNamePrefix(),
+                "调度池与文件作业池线程名前缀隔离");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_normal_repeated_operation_is_idempotent() throws Exception {
+        // 幂等：同一任务重复提交各自独立执行一次，不合并不丢失，
+        // 线程数不因重复提交而扩张。
+        ThreadPoolTaskExecutor dispatch = newDispatch(2, 100);
+        AtomicInteger count = new AtomicInteger();
+        CountDownLatch all = new CountDownLatch(3);
+        Runnable task = () -> {
+            count.incrementAndGet();
+            all.countDown();
+        };
+        dispatch.execute(task);
+        dispatch.execute(task);
+        dispatch.execute(task);
+        assertTrue(all.await(5, TimeUnit.SECONDS), "同一任务重复提交各自执行一次");
+        assertEquals(3, count.get());
+        assertEquals(2, dispatch.getMaxPoolSize(), "重复提交不扩张线程数");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_boundary_empty_input() throws Exception {
+        // 空输入：容量配置为 0 时统一钳制到最小值，池仍可用。
+        ThreadPoolTaskScheduler scheduler = newScheduler(0);
+        assertEquals(1, scheduler.getScheduledThreadPoolExecutor().getCorePoolSize(), "调度池 0 钳制到 1");
+        ThreadPoolTaskExecutor dispatch = newDispatch(0, 0);
+        assertEquals(1, dispatch.getCorePoolSize(), "文件作业池 0 钳制到 1");
+        assertEquals(10, dispatch.getQueueCapacity(), "队列 0 钳制到 10");
+        ExecutorService cozeVirtual = newCozeVirtual();
+        TaskExecutor coze = newCoze(cozeVirtual, 0);
+        CountDownLatch done = new CountDownLatch(1);
+        coze.execute(done::countDown);
+        assertTrue(done.await(5, TimeUnit.SECONDS), "Coze 池 0 钳制到 1 后仍可执行");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_boundary_single_item() throws Exception {
+        // 单元素：单线程池单任务直接完成，不依赖批量路径。
+        ThreadPoolTaskExecutor dispatch = newDispatch(1, 10);
+        CountDownLatch done = new CountDownLatch(1);
+        dispatch.execute(done::countDown);
+        assertTrue(done.await(5, TimeUnit.SECONDS), "单线程池单任务直接完成");
+        assertEquals(1, dispatch.getCorePoolSize());
+
+        ThreadPoolTaskScheduler scheduler = newScheduler(1);
+        CountDownLatch scheduled = new CountDownLatch(1);
+        scheduler.schedule((Runnable) scheduled::countDown, new Date(System.currentTimeMillis() + 30));
+        assertTrue(scheduled.await(5, TimeUnit.SECONDS), "单线程调度池单次调度完成");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_boundary_limit_and_overflow() throws Exception {
+        // 上限/超限：文件作业池 2 线程 + 队列 10，容量为 12；
+        // 第 13 个提交被拒绝（TaskRejectedException），不发生无界堆积。
+        ThreadPoolTaskExecutor dispatch = newDispatch(2, 10);
+        CountDownLatch blockersRunning = new CountDownLatch(2);
+        CountDownLatch releaseBlockers = new CountDownLatch(1);
+        CountDownLatch allDone = new CountDownLatch(12);
+        for (int i = 0; i < 2; i++) {
+            dispatch.execute(() -> {
+                blockersRunning.countDown();
+                try {
+                    releaseBlockers.await(10, TimeUnit.SECONDS);
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+                allDone.countDown();
+            });
+        }
+        assertTrue(blockersRunning.await(5, TimeUnit.SECONDS), "两个运行线程占位");
+        for (int i = 0; i < 10; i++) {
+            dispatch.execute(allDone::countDown);
+        }
+        assertThrows(TaskRejectedException.class, () -> dispatch.execute(allDone::countDown),
+                "队列满后拒绝新提交，不发生无界堆积");
+        releaseBlockers.countDown();
+        assertTrue(allDone.await(10, TimeUnit.SECONDS), "已受理的 12 个任务全部完成");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_invalid_input_rejected() throws Exception {
+        // 非法参数：负容量统一钳制到最小值（不崩溃、行为确定）；
+        // null 任务直接被拒绝。
+        ThreadPoolTaskScheduler scheduler = newScheduler(-1);
+        assertEquals(1, scheduler.getScheduledThreadPoolExecutor().getCorePoolSize(), "负值钳制到最小值");
+        ThreadPoolTaskExecutor dispatch = newDispatch(-2, -5);
+        assertEquals(1, dispatch.getCorePoolSize());
+        assertEquals(10, dispatch.getQueueCapacity());
+
+        ExecutorService cozeVirtual = newCozeVirtual();
+        TaskExecutor coze = newCoze(cozeVirtual, -3);
+        assertThrows(IllegalArgumentException.class, () -> coze.execute(null), "null 任务被拒绝");
+        CountDownLatch done = new CountDownLatch(1);
+        coze.execute(done::countDown);
+        assertTrue(done.await(5, TimeUnit.SECONDS), "非法配置钳制后池仍可用");
+    }
+
+    @Test
+    void test_task_074_image_dispatch_job_dependency_failure_releases_resources() throws Exception {
+        // 依赖失败：Coze 任务抛异常后信号量名额必须释放（后续任务可执行）；
+        // 调度任务异常被 error handler 吞掉，调度器继续可用。
+        ExecutorService cozeVirtual = newCozeVirtual();
+        TaskExecutor coze = newCoze(cozeVirtual, 2);
+        CountDownLatch blockerHeld = new CountDownLatch(1);
+        CountDownLatch releaseBlocker = new CountDownLatch(1);
+        coze.execute(() -> {
+            blockerHeld.countDown();
+            try {
+                releaseBlocker.await(10, TimeUnit.SECONDS);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        });
+        assertTrue(blockerHeld.await(5, TimeUnit.SECONDS), "任务 1 占住一个信号量名额");
+        coze.execute(() -> {
+            throw new IllegalStateException("coze down");
+        });
+        CountDownLatch afterFailure = new CountDownLatch(1);
+        coze.execute(afterFailure::countDown);
+        assertTrue(afterFailure.await(5, TimeUnit.SECONDS), "失败任务释放名额，后续任务可执行");
+        releaseBlocker.countDown();
+
+        ThreadPoolTaskScheduler scheduler = newScheduler(2);
+        AtomicBoolean secondRan = new AtomicBoolean(false);
+        CountDownLatch secondDone = new CountDownLatch(1);
+        scheduler.schedule(() -> {
+            throw new IllegalStateException("scheduled boom");
+        }, new Date(System.currentTimeMillis() + 30));
+        scheduler.schedule(() -> {
+            secondRan.set(true);
+            secondDone.countDown();
+        }, new Date(System.currentTimeMillis() + 60));
+        assertTrue(secondDone.await(5, TimeUnit.SECONDS), "调度任务异常被 error handler 吞掉，调度器继续可用");
+        assertTrue(secondRan.get());
+    }
+}