diff --git a/app/core/logging.py b/app/core/logging.py
index 0981021..56b856b 100644
--- a/app/core/logging.py
+++ b/app/core/logging.py
@@ -1,20 +1,91 @@
 """统一日志配置。
 
-业务代码用 `logger = logging.getLogger("shagua.xxx")` 即可,本模块在 main.py 启动时调一次。
+业务代码用 `logger = logging.getLogger("shagua.xxx")` 即可, 本模块在 main.py 启动时调一次。
+
+- 控制台(stdout): 人类可读文本, 给 systemd / 本地看。
+- 文件 `logs/app-server.log`: 单行 JSON, 供阿里云 SLS/Logtail 采集(JSON 模式零正则);
+  异常栈作为字段内嵌不换行 → 每条日志一行。
+- 环境变量:
+  - LOG_JSON_CONSOLE=1   控制台也输出 JSON
+  - LOG_DIR / LOG_FILE   改落盘路径(默认 logs/app-server.log)
+    ⚠️ admin 子进程(app.admin.main, 独立进程)应设不同 LOG_FILE, 避免与主进程争抢同一轮转文件
+  - LOG_SERVICE_NAME     JSON 里的 service 字段(默认 app-server)
 """
 from __future__ import annotations
 
+import json
 import logging
+import os
 import sys
+from datetime import datetime
+from logging.handlers import RotatingFileHandler
+from pathlib import Path
+
+
+class JsonFormatter(logging.Formatter):
+    """把 LogRecord 序列化成单行 JSON(SLS/Logtail 友好)。异常栈内嵌为字段, 整条仍是一行。"""
+    def __init__(self, service: str = "app-server"):
+        super().__init__()
+        self.service = service
+
+    def format(self, record: logging.LogRecord) -> str:
+        dt = datetime.fromtimestamp(record.created)
+        data = {
+            "time": dt.strftime("%Y-%m-%dT%H:%M:%S.") + f"{int(record.msecs):03d}",
+            "level": record.levelname,
+            "service": self.service,
+            "logger": record.name,
+            "func": record.funcName,
+            "line": record.lineno,
+            "message": record.getMessage(),
+        }
+        if record.exc_info:
+            data["exception"] = self.formatException(record.exc_info)
+        if record.stack_info:
+            data["stack"] = self.formatStack(record.stack_info)
+        return json.dumps(data, ensure_ascii=False, default=str)
+
+
+_CONFIGURED = False
 
 
 def setup_logging(debug: bool = False) -> None:
+    global _CONFIGURED
+    if _CONFIGURED:
+        return
+
     level = logging.DEBUG if debug else logging.INFO
-    logging.basicConfig(
-        level=level,
-        format="%(asctime)s %(levelname)s %(name)s: %(message)s",
-        stream=sys.stdout,
+    service = os.getenv("LOG_SERVICE_NAME", "app-server")
+
+    root = logging.getLogger()
+    root.setLevel(level)
+    # 清掉 basicConfig/uvicorn 可能预置的 root handler, 避免重复输出
+    for h in list(root.handlers):
+        root.removeHandler(h)
+
+    # 控制台: 默认文本(systemd/本地看); LOG_JSON_CONSOLE=1 时输出 JSON
+    console = logging.StreamHandler(sys.stdout)
+    if os.getenv("LOG_JSON_CONSOLE") == "1":
+        console.setFormatter(JsonFormatter(service))
+    else:
+        console.setFormatter(
+            logging.Formatter("%(asctime)s %(levelname)s %(name)s: %(message)s")
+        )
+    root.addHandler(console)
+
+    # 文件: 单行 JSON, 供 Logtail 采集(自动轮转, 单文件 10MB, 保留 5 个)
+    log_file = os.getenv("LOG_FILE") or str(
+        Path(os.getenv("LOG_DIR", "logs")) / "app-server.log"
     )
+    Path(log_file).parent.mkdir(parents=True, exist_ok=True)
+    file_handler = RotatingFileHandler(
+        log_file, maxBytes=10 * 1024 * 1024, backupCount=5, encoding="utf-8",
+    )
+    file_handler.setFormatter(JsonFormatter(service))
+    root.addHandler(file_handler)
+
     # 第三方库降噪
     logging.getLogger("httpx").setLevel(logging.WARNING)
     logging.getLogger("httpcore").setLevel(logging.WARNING)
+
+    _CONFIGURED = True