diff --git a/backend-single/src/main/java/com/emotion/exception/GlobalExceptionHandler.java b/backend-single/src/main/java/com/emotion/exception/GlobalExceptionHandler.java
index 13da8bd..a301086 100644
--- a/backend-single/src/main/java/com/emotion/exception/GlobalExceptionHandler.java
+++ b/backend-single/src/main/java/com/emotion/exception/GlobalExceptionHandler.java
@@ -72,6 +72,45 @@ public class GlobalExceptionHandler {
         }
     }
 
+    /**
+     * 处理微信 API 异常（业务错误 400 / 内部错误 500 / 上游错误 502）
+     *
+     * <p>根据异常内部 code 映射到不同友好提示（不直接暴露原始异常消息给前端）：
+     * <ul>
+     *   <li>400 - 微信业务错误（如 errcode 40029 invalid code）："微信授权失败，请重试"</li>
+     *   <li>500 - 内部 JSON 解析失败："微信登录失败，请重试"</li>
+     *   <li>502 - 网络异常 / 非 2xx / Content-Type 不是 JSON："微信服务暂不可用，请稍后重试"</li>
+     * </ul>
+     *
+     * <p>详细异常消息仅记录到日志（含 [WeChatAPI] 前缀），前端仅看到友好提示。
+     */
+    @ExceptionHandler(WechatApiException.class)
+    public Result<Void> handleWechatApiException(WechatApiException e, HttpServletRequest request) {
+        String userMessage;
+        switch (e.getCode()) {
+            case 400:
+                userMessage = "微信授权失败，请重试";
+                log.warn("[WeChatAPI] 微信授权失败，code={}, method={}, uri={}, detail={}",
+                    e.getCode(), request.getMethod(), request.getRequestURI(), e.getMessage());
+                return Result.badRequest(userMessage);
+            case 500:
+                userMessage = "微信登录失败，请重试";
+                log.warn("[WeChatAPI] 微信登录内部错误，code={}, method={}, uri={}, detail={}",
+                    e.getCode(), request.getMethod(), request.getRequestURI(), e.getMessage());
+                return Result.error(userMessage);
+            case 502:
+                userMessage = "微信服务暂不可用，请稍后重试";
+                log.warn("[WeChatAPI] 微信服务上游错误，code={}, method={}, uri={}, detail={}",
+                    e.getCode(), request.getMethod(), request.getRequestURI(), e.getMessage());
+                return Result.error(e.getCode(), userMessage);
+            default:
+                userMessage = "微信登录异常，请重试";
+                log.warn("[WeChatAPI] 微信登录未知错误，code={}, method={}, uri={}, detail={}",
+                    e.getCode(), request.getMethod(), request.getRequestURI(), e.getMessage());
+                return Result.error(userMessage);
+        }
+    }
+
     /**
      * 处理参数校验异常
      */
diff --git a/backend-single/src/test/java/com/emotion/exception/GlobalExceptionHandlerWechatTest.java b/backend-single/src/test/java/com/emotion/exception/GlobalExceptionHandlerWechatTest.java
new file mode 100644
index 0000000..815fc3a
--- /dev/null
+++ b/backend-single/src/test/java/com/emotion/exception/GlobalExceptionHandlerWechatTest.java
@@ -0,0 +1,72 @@
+package com.emotion.exception;
+
+import com.emotion.common.Result;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.mock.web.MockHttpServletRequest;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * GlobalExceptionHandler 的 WechatApiException handler 单元测试
+ *
+ * 验证：
+ * 1. 400 业务错误 → "微信授权失败，请重试"
+ * 2. 500 内部错误 → "微信登录失败，请重试"
+ * 3. 502 上游错误 → "微信服务暂不可用，请稍后重试"
+ */
+@ExtendWith(MockitoExtension.class)
+class GlobalExceptionHandlerWechatTest {
+
+    @InjectMocks
+    private GlobalExceptionHandler handler;
+
+    private MockHttpServletRequest request;
+
+    @BeforeEach
+    void setUp() {
+        request = new MockHttpServletRequest();
+        request.setMethod("POST");
+        request.setRequestURI("/api/wechat/login");
+    }
+
+    @Test
+    void handleWechatApiException_Code400_ReturnsBadRequestWithFriendlyMessage() {
+        WechatApiException ex = new WechatApiException(400, "errcode=40029, errmsg=invalid code (internal detail)", "");
+
+        Result<?> result = handler.handleWechatApiException(ex, request);
+
+        assertNotNull(result);
+        assertEquals("微信授权失败，请重试", result.getMessage());
+        // Ensure internal detail is NOT exposed to frontend
+        assertFalse(result.getMessage().contains("errcode"));
+        assertFalse(result.getMessage().contains("40029"));
+    }
+
+    @Test
+    void handleWechatApiException_Code500_ReturnsInternalErrorWithFriendlyMessage() {
+        WechatApiException ex = new WechatApiException(500, "JSON parse failure at line 1 (internal detail)", "");
+
+        Result<?> result = handler.handleWechatApiException(ex, request);
+
+        assertNotNull(result);
+        assertEquals("微信登录失败，请重试", result.getMessage());
+        assertFalse(result.getMessage().contains("JSON"));
+        assertFalse(result.getMessage().contains("parse"));
+    }
+
+    @Test
+    void handleWechatApiException_Code502_ReturnsBadGatewayWithFriendlyMessage() {
+        WechatApiException ex = new WechatApiException(502, "Connection refused: api.weixin.qq.com (internal detail)", "");
+
+        Result<?> result = handler.handleWechatApiException(ex, request);
+
+        assertNotNull(result);
+        assertEquals("微信服务暂不可用，请稍后重试", result.getMessage());
+        assertFalse(result.getMessage().contains("Connection"));
+        assertFalse(result.getMessage().contains("refused"));
+    }
+}