diff --git a/sdk/app/services/figures.py b/sdk/app/services/figures.py
index 3902f23..03bce7b 100644
--- a/sdk/app/services/figures.py
+++ b/sdk/app/services/figures.py
@@ -48,7 +48,7 @@ PROXY_PATH = "/api/figures/proxy?pmcid={pmcid}&url={url}"
 
 _cache: dict[str, dict[str, Any]] = {}  # pmcid -> {ts, figures, license}
 _local_index: dict[str, list[dict]] | None = None  # pmcid数字 -> 本地图片清单
-EXTERNAL_TIMEOUT = 5.0
+EXTERNAL_TIMEOUT = 15.0  # 176 实测 EBI 2-8s 波动，5s 必超时（2026-09-12 S2 部署质检）
 CACHE_TTL = 3600.0