diff --git a/config/platform-infra/webterm.yaml b/config/platform-infra/webterm.yaml
index db632607..d3339a65 100644
--- a/config/platform-infra/webterm.yaml
+++ b/config/platform-infra/webterm.yaml
@@ -49,6 +49,7 @@ browserOutputPolicy:
 browserPerformance:
   animationsEnabled: true
   defaultBackgroundMode: receive-only
+  defaultMobileTerminalPercent: 40
   backgroundModes:
     disconnect:
       label: 断开后台连接
diff --git a/scripts/src/platform-infra-webterm.ts b/scripts/src/platform-infra-webterm.ts
index d49a14a8..f9de54e8 100644
--- a/scripts/src/platform-infra-webterm.ts
+++ b/scripts/src/platform-infra-webterm.ts
@@ -67,6 +67,7 @@ interface BrowserOutputPolicy {
 interface BrowserPerformance {
   animationsEnabled: boolean;
   defaultBackgroundMode: "disconnect" | "receive-only" | "low-frequency" | "live";
+  defaultMobileTerminalPercent: number;
   backgroundModes: Array<{ id: "disconnect" | "receive-only" | "low-frequency" | "live"; label: string }>;
   deferredOutputMaxBytes: number;
   lowFrequencyRenderIntervalMs: number;
@@ -898,6 +899,7 @@ function parseBrowserPerformance(record: Record<string, unknown>, path: string):
   return {
     animationsEnabled: booleanField(record, "animationsEnabled", path),
     defaultBackgroundMode: defaultBackgroundMode as BrowserPerformance["defaultBackgroundMode"],
+    defaultMobileTerminalPercent: integerInRangeField(record, "defaultMobileTerminalPercent", path, 20, 70),
     backgroundModes,
     deferredOutputMaxBytes: positiveIntegerField(record, "deferredOutputMaxBytes", path),
     lowFrequencyRenderIntervalMs: positiveIntegerField(record, "lowFrequencyRenderIntervalMs", path),
@@ -913,6 +915,12 @@ function positiveIntegerField(record: Record<string, unknown>, key: string, path
   return value;
 }
 
+function integerInRangeField(record: Record<string, unknown>, key: string, path: string, min: number, max: number): number {
+  const value = integerField(record, key, path);
+  if (value < min || value > max) throw new Error(`${path}.${key} must be from ${min} to ${max}`);
+  return value;
+}
+
 function parseLiteral<T extends string>(value: string, expected: T, path: string): T {
   if (value !== expected) throw new Error(`${path} must be ${expected}`);
   return expected;