diff --git a/backend-single/src/main/java/com/emotion/interceptor/WechatApiLoggingInterceptor.java b/backend-single/src/main/java/com/emotion/interceptor/WechatApiLoggingInterceptor.java
new file mode 100644
index 0000000..f268649
--- /dev/null
+++ b/backend-single/src/main/java/com/emotion/interceptor/WechatApiLoggingInterceptor.java
@@ -0,0 +1,69 @@
+package com.emotion.interceptor;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpRequest;
+import org.springframework.http.client.ClientHttpRequestExecution;
+import org.springframework.http.client.ClientHttpRequestInterceptor;
+import org.springframework.http.client.ClientHttpResponse;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.regex.Pattern;
+
+/**
+ * 微信 API HTTP 请求 / 响应日志拦截器
+ *
+ * <p>设计要点：
+ * <ol>
+ *   <li>配合 BufferingClientHttpRequestFactory 使用，body 可被多次读取</li>
+ *   <li>URL / method / status / content-type 用 INFO 级别（生产可见）</li>
+ *   <li>body 用 DEBUG 级别（生产默认不输出，避免日志膨胀）</li>
+ *   <li>body 中敏感字段（session_key / openid / unionid / access_token / refresh_token）脱敏</li>
+ * </ol>
+ */
+@Slf4j
+public class WechatApiLoggingInterceptor implements ClientHttpRequestInterceptor {
+
+    private static final int MAX_BODY_LOG = 2048;
+    private static final Pattern SENSITIVE_FIELDS = Pattern.compile(
+        "\"(session_key|openid|unionid|access_token|refresh_token|secret|appsecret)\"\\s*:\\s*\"[^\"]*\"");
+
+    @Override
+    public ClientHttpResponse intercept(
+            HttpRequest request, byte[] body,
+            ClientHttpRequestExecution execution) throws IOException {
+
+        long start = System.currentTimeMillis();
+        log.info("[WeChatAPI] ---> {} {}", request.getMethod(), request.getURI());
+
+        ClientHttpResponse response = execution.execute(request, body);
+        long duration = System.currentTimeMillis() - start;
+
+        log.info("[WeChatAPI] <--- {} {} ({}ms) content-type={}",
+            response.getStatusCode(), request.getURI(), duration,
+            response.getHeaders().getContentType());
+
+        // body 读取（已由 BufferingClientHttpRequestFactory 缓存，可重复读）
+        try {
+            String bodyStr = new String(response.getBody().readAllBytes(), StandardCharsets.UTF_8);
+            if (bodyStr.length() > MAX_BODY_LOG) {
+                bodyStr = bodyStr.substring(0, MAX_BODY_LOG) + "...(truncated)";
+            }
+            log.debug("[WeChatAPI] body={}", desensitize(bodyStr));
+        } catch (IOException e) {
+            log.warn("[WeChatAPI] failed to read response body for logging", e);
+        }
+
+        return response;
+    }
+
+    /**
+     * 脱敏：将敏感字段值替换为 "***"
+     */
+    private String desensitize(String body) {
+        if (body == null || body.isEmpty()) {
+            return body;
+        }
+        return SENSITIVE_FIELDS.matcher(body).replaceAll("\"$1\":\"***\"");
+    }
+}
diff --git a/backend-single/src/test/java/com/emotion/interceptor/WechatApiLoggingInterceptorTest.java b/backend-single/src/test/java/com/emotion/interceptor/WechatApiLoggingInterceptorTest.java
new file mode 100644
index 0000000..8deeb02
--- /dev/null
+++ b/backend-single/src/test/java/com/emotion/interceptor/WechatApiLoggingInterceptorTest.java
@@ -0,0 +1,106 @@
+package com.emotion.interceptor;
+
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Method;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * WechatApiLoggingInterceptor 单元测试
+ *
+ * 注：desensitize() 是 private 方法，通过反射测试
+ */
+class WechatApiLoggingInterceptorTest {
+
+    @Test
+    void desensitize_shouldMaskSessionKey() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        String input = "{\"openid\":\"oXyz123\",\"session_key\":\"abc@456\"}";
+        String result = (String) method.invoke(interceptor, input);
+
+        assertNotNull(result);
+        assertTrue(result.contains("\"openid\":\"***\""), "openid 应被脱敏: " + result);
+        assertTrue(result.contains("\"session_key\":\"***\""), "session_key 应被脱敏: " + result);
+    }
+
+    @Test
+    void desensitize_shouldMaskAccessToken() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        String input = "{\"access_token\":\"ACCESS-123\",\"refresh_token\":\"REFRESH-456\"}";
+        String result = (String) method.invoke(interceptor, input);
+
+        assertTrue(result.contains("\"access_token\":\"***\""));
+        assertTrue(result.contains("\"refresh_token\":\"***\""));
+    }
+
+    @Test
+    void desensitize_shouldHandleNull() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        assertEquals(null, method.invoke(interceptor, (Object) null));
+    }
+
+    @Test
+    void desensitize_shouldNotModifyNonSensitiveFields() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        String input = "{\"errcode\":40013,\"errmsg\":\"invalid appid\"}";
+        String result = (String) method.invoke(interceptor, input);
+
+        assertEquals(input, result, "非敏感字段不应被修改");
+    }
+
+    @Test
+    void desensitize_shouldNotMatchAccessTokenV2() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        // 验证 access_token_v2 不会被 access_token 模式误匹配
+        String input = "{\"access_token_v2\":\"PUBLIC_VALUE\",\"my_reset_secret\":\"OK\"}";
+        String result = (String) method.invoke(interceptor, input);
+
+        // access_token_v2 不应被脱敏（正则精确匹配完整 key 名称）
+        // my_reset_secret 也不应被脱敏（正则需要精确匹配 "secret" 而非子串）
+        assertTrue(result.contains("\"access_token_v2\":\"PUBLIC_VALUE\""), "access_token_v2 不应被脱敏: " + result);
+        assertTrue(result.contains("\"my_reset_secret\":\"OK\""), "my_reset_secret 不应被脱敏: " + result);
+    }
+
+    @Test
+    void desensitize_shouldHandleEmptyString() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        String result = (String) method.invoke(interceptor, "");
+        assertEquals("", result, "空字符串应原样返回");
+    }
+
+    @Test
+    void desensitize_shouldMaskMultipleSensitiveFieldsSimultaneously() throws Exception {
+        WechatApiLoggingInterceptor interceptor = new WechatApiLoggingInterceptor();
+        Method method = WechatApiLoggingInterceptor.class.getDeclaredMethod("desensitize", String.class);
+        method.setAccessible(true);
+
+        String input = "{\"openid\":\"o123\",\"access_token\":\"tok\",\"unionid\":\"uni456\",\"refresh_token\":\"ref789\"}";
+        String result = (String) method.invoke(interceptor, input);
+
+        assertTrue(result.contains("\"openid\":\"***\""));
+        assertTrue(result.contains("\"access_token\":\"***\""));
+        assertTrue(result.contains("\"unionid\":\"***\""));
+        assertTrue(result.contains("\"refresh_token\":\"***\""));
+    }
+}