diff --git a/utils/sehuatang/shehuatang_undetected.py b/utils/sehuatang/shehuatang_undetected.py
index 1518b3a..a5f20b3 100644
--- a/utils/sehuatang/shehuatang_undetected.py
+++ b/utils/sehuatang/shehuatang_undetected.py
@@ -25,6 +25,11 @@ from PIL import Image as PILImage
 import re
 from PyPDF2 import PdfReader, PdfWriter
 from loguru import logger
+from urllib.parse import urlparse
+from requests.adapters import HTTPAdapter
+from urllib3.util import Retry
+
+UNREACHABLE_HOSTS = set()
 
 
 def download_image(url, session):
@@ -32,9 +37,25 @@ def download_image(url, session):
     try:
         if not url.lower().endswith(('.jpg', '.jpeg', '.png')):
             return None
-        response = session.get(url, timeout=15)
+        parsed = urlparse(url)
+        host = parsed.netloc.lower()
+        if host in UNREACHABLE_HOSTS:
+            return None
+        headers = {'Referer': f'{parsed.scheme}://{host}/'}
+        response = session.get(url, headers=headers, timeout=10)
         response.raise_for_status()
         return BytesIO(response.content)
+    except requests.exceptions.RequestException as e:
+        try:
+            parsed = urlparse(url)
+            host = parsed.netloc.lower()
+            msg = str(e)
+            if 'Network is unreachable' in msg or 'Failed to establish a new connection' in msg:
+                UNREACHABLE_HOSTS.add(host)
+        except Exception:
+            pass
+        logger.warning(f"下载图片失败: {e}")
+        return None
     except Exception as e:
         logger.warning(f"下载图片失败: {e}")
         return None
@@ -133,7 +154,16 @@ def fetch_and_create_pdf(url):
         # 同步 Session
         session = requests.Session()
         ua = driver.execute_script("return navigator.userAgent")
-        session.headers.update({'User-Agent': ua, 'Referer': 'https://tu.ymawv.la/'})
+        session.headers.update({
+            'User-Agent': ua,
+            'Accept': 'image/avif,image/webp,image/apng,image/svg+xml,image/*;q=0.8,*/*;q=0.5',
+            'Accept-Language': 'zh-CN,zh;q=0.9',
+            'Connection': 'keep-alive'
+        })
+        retry = Retry(total=3, connect=3, read=3, backoff_factor=0.5, status_forcelist=[429, 500, 502, 503, 504], allowed_methods=frozenset(['GET']))
+        adapter = HTTPAdapter(max_retries=retry)
+        session.mount('https://', adapter)
+        session.mount('http://', adapter)
         for c in driver.get_cookies():
             session.cookies.set(c['name'], c['value'])