diff --git a/backend-java/src/main/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolver.java b/backend-java/src/main/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolver.java
new file mode 100644
index 00000000..7a17aab6
--- /dev/null
+++ b/backend-java/src/main/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolver.java
@@ -0,0 +1,61 @@
+package com.nanri.aiimage.config;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+/**
+ * 图片下载客户端统一配置解析（task-171）。
+ *
+ * 真实基线（已核实，对应 task-166 契约表"图片下载"行）：SimilarAsinImageEmbedder 使用自建
+ * OkHttpClient（不参与共享 JDK HttpClientPool），connect/read/write 均取
+ * aiimage.similar-asin.image-download-timeout-seconds（默认 5s），call = 2×download；
+ * 整批预取预算 image-prefetch-timeout-seconds（默认 1800s）；无显式次数重试
+ * （OkHttp retryOnConnectionFailure + 上游批次重提）。
+ *
+ * 语义：模块级现有配置优先（保证接入切点时行为不变），命名空间 aiimage.http-client.* 兜底。
+ * 次数重试/退避来自命名空间，为未来接入切点预留；当前不改变 SimilarAsinImageEmbedder 调用点。
+ */
+@Component
+@RequiredArgsConstructor
+public class ImageDownloadHttpConfigResolver {
+
+    private final HttpClientProperties httpClientProperties;
+    private final SimilarAsinProperties similarAsinProperties;
+
+    private int downloadSeconds() {
+        return similarAsinProperties.getImageDownloadTimeoutSeconds();
+    }
+
+    /** 连接超时：模块 download 秒数优先（现状 5s）；未配置回退命名空间。 */
+    public long connectTimeoutMillis() {
+        int module = downloadSeconds();
+        return module > 0 ? module * 1_000L : httpClientProperties.effectiveConnectTimeoutMillis();
+    }
+
+    /** 读取超时：模块 download 秒数优先（现状 5s）；未配置回退命名空间。 */
+    public long readTimeoutMillis() {
+        int module = downloadSeconds();
+        return module > 0 ? module * 1_000L : httpClientProperties.effectiveReadTimeoutMillis();
+    }
+
+    /** 调用总超时：模块 download×2（现状 10s）；未配置回退命名空间。 */
+    public long callTimeoutMillis() {
+        int module = downloadSeconds();
+        return module > 0 ? module * 2_000L : httpClientProperties.effectiveCallTimeoutMillis();
+    }
+
+    /** 整批图片预取预算（秒转毫秒）：模块优先（现状 1800s）；未配置回退命名空间 read。 */
+    public long prefetchTimeoutMillis() {
+        int module = similarAsinProperties.getImagePrefetchTimeoutSeconds();
+        return module > 0 ? module * 1_000L : httpClientProperties.effectiveReadTimeoutMillis();
+    }
+
+    /** 次数重试：来自命名空间（现状图片下载无次数重试，OkHttp 仅连接失败自愈）。 */
+    public int maxRetries() {
+        return httpClientProperties.effectiveMaxRetries();
+    }
+
+    public long baseRetryDelayMillis() {
+        return httpClientProperties.getBaseRetryDelayMillis();
+    }
+}
diff --git a/backend-java/src/test/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolverTest.java b/backend-java/src/test/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolverTest.java
new file mode 100644
index 00000000..bca8be84
--- /dev/null
+++ b/backend-java/src/test/java/com/nanri/aiimage/config/ImageDownloadHttpConfigResolverTest.java
@@ -0,0 +1,100 @@
+package com.nanri.aiimage.config;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * task-171：图片下载客户端配置接入契约（plan 10，诚实模式）。
+ *
+ * 现网真实基线（已核实，对应 task-166 契约表"图片下载"行）：
+ *  - SimilarAsinImageEmbedder 用自建 OkHttpClient（非共享 JDK 池）：connect/read/write =
+ *    aiimage.similar-asin.image-download-timeout-seconds（默认 5s），call = 2×download（10s）；
+ *  - 整批预取预算 aiimage.similar-asin.image-prefetch-timeout-seconds（默认 1800s）；
+ *  - 无显式次数重试（依赖 OkHttp retryOnConnectionFailure + 上游批次重提），图片缓存幂等。
+ *
+ * resolver 语义：模块级现有配置优先（保证接入切点行为不变），命名空间 aiimage.http-client.*
+ * 兜底；不改动 SimilarAsinImageEmbedder 调用点，仅提供稳定访问面。
+ */
+class ImageDownloadHttpConfigResolverTest {
+
+    private HttpClientProperties http;
+    private SimilarAsinProperties similarAsin;
+    private ImageDownloadHttpConfigResolver resolver;
+
+    @BeforeEach
+    void setUp() {
+        http = new HttpClientProperties();
+        similarAsin = new SimilarAsinProperties();
+        resolver = new ImageDownloadHttpConfigResolver(http, similarAsin);
+    }
+
+    @Test
+    void defaultsMatchCurrentEmbedder() {
+        // 模块默认 imageDownloadTimeoutSeconds=5 → OkHttp connect/read 5s、call 10s
+        assertEquals(5_000L, resolver.readTimeoutMillis());
+        assertEquals(5_000L, resolver.connectTimeoutMillis());
+        assertEquals(10_000L, resolver.callTimeoutMillis());
+    }
+
+    @Test
+    void prefetchBudgetFromModule() {
+        // 模块默认 imagePrefetchTimeoutSeconds=1800 → 1800s
+        assertEquals(1_800_000L, resolver.prefetchTimeoutMillis());
+    }
+
+    @Test
+    void moduleWinsOverNamespace() {
+        // 模块级现有配置优先：命名空间 read 调大不影响图片下载 read（行为不变）
+        http.setReadTimeoutMillis(120_000);
+        assertEquals(5_000L, resolver.readTimeoutMillis());
+    }
+
+    @Test
+    void downloadOverrideTakesEffect() {
+        similarAsin.setImageDownloadTimeoutSeconds(8);
+        assertEquals(8_000L, resolver.readTimeoutMillis());
+        assertEquals(8_000L, resolver.connectTimeoutMillis());
+        assertEquals(16_000L, resolver.callTimeoutMillis(), "call = 2×download");
+    }
+
+    @Test
+    void fallsBackToNamespaceWhenModuleUnset() {
+        // 模块未配置(<=0) → 命名空间（默认 connect 10s/read 60s/call 90s）
+        similarAsin.setImageDownloadTimeoutSeconds(0);
+        similarAsin.setImagePrefetchTimeoutSeconds(0);
+        assertEquals(10_000L, resolver.connectTimeoutMillis());
+        assertEquals(60_000L, resolver.readTimeoutMillis());
+        assertEquals(90_000L, resolver.callTimeoutMillis());
+        assertEquals(60_000L, resolver.prefetchTimeoutMillis());
+    }
+
+    @Test
+    void retryFromNamespaceClamped() {
+        // 无显式次数重试是现状；次数来自命名空间，供未来接入切点
+        assertEquals(3, resolver.maxRetries());
+        http.setMaxRetries(99);
+        assertEquals(10, resolver.maxRetries(), "命名空间重试钳制到 10");
+        assertEquals(500L, resolver.baseRetryDelayMillis());
+    }
+
+    @Test
+    void invalidNamespaceTimeoutsClamped() {
+        similarAsin.setImageDownloadTimeoutSeconds(0);
+        similarAsin.setImagePrefetchTimeoutSeconds(0);
+        http.setConnectTimeoutMillis(-1);
+        assertEquals(1_000L, resolver.connectTimeoutMillis());
+        http.setReadTimeoutMillis(999_999_999L);
+        assertEquals(3_600_000L, resolver.readTimeoutMillis());
+    }
+
+    @Test
+    void resolverWiredAsStableAccessSurface() {
+        assertTrue(resolver.connectTimeoutMillis() > 0);
+        assertTrue(resolver.readTimeoutMillis() > 0);
+        assertTrue(resolver.callTimeoutMillis() > 0);
+        assertTrue(resolver.maxRetries() >= 0);
+    }
+}