diff --git a/launch_openpilot.sh b/launch_openpilot.sh
index ee6df1dcb..21cbc52f5 100755
--- a/launch_openpilot.sh
+++ b/launch_openpilot.sh
@@ -8,6 +8,8 @@ echo -n "0.2.0" > /data/params/d/CompletedTrainingVersion
 echo -n "1.0" > /data/params/d/CompletedSunnylinkConsentVersion  # Sunnylink 同意
 echo -n "1" > /data/params/d/IsMetric
 echo -n "1" > /data/params/d/ToyotaEnforceStockLongitudinal
+# 默认 UI 语言：简体中文（仅当尚未设置时写入，保留应用内的语言切换）
+[ -f /data/params/d/LanguageSetting ] || echo -n "zh-CHS" > /data/params/d/LanguageSetting