diff --git a/app/tool/image_download.py b/app/tool/image_download.py
new file mode 100644
index 0000000..d0c19cc
--- /dev/null
+++ b/app/tool/image_download.py
@@ -0,0 +1,36 @@
+"""图片下载工具。
+
+把图片 URL 下载成字节流，供 OCR（app.tool.ocr）与二维码识别
+（app.tool.cv / app.tool.qr_decode）直接消费，不落盘。
+"""
+
+from __future__ import annotations
+
+import httpx
+
+from app.core.logger import log
+
+# 请求超时（秒）
+_TIMEOUT = 20
+
+
+def download_image(url: str) -> bytes | None:
+    """下载图片。
+
+    Args:
+        url: 图片地址。
+
+    Returns:
+        图片字节流；下载失败时返回 None。
+    """
+    if not url or not url.startswith("http"):
+        return None
+
+    try:
+        with httpx.Client(timeout=_TIMEOUT, follow_redirects=True) as client:
+            response = client.get(url)
+            response.raise_for_status()
+            return response.content or None
+    except httpx.HTTPError as exc:
+        log.warning(f"图片下载失败: {url} | {exc}")
+        return None