diff --git a/local-tool/server/internal/driver/kneron/kl720_driver.go b/local-tool/server/internal/driver/kneron/kl720_driver.go
index a4b3cc5..5f2ab30 100644
--- a/local-tool/server/internal/driver/kneron/kl720_driver.go
+++ b/local-tool/server/internal/driver/kneron/kl720_driver.go
@@ -289,14 +289,27 @@ func (d *KneronDriver) Connect() error {
 	d.mu.Unlock()
 
 	// First connect after server start: reset device to clear stale models.
-	if needsReset {
-		d.driverLog("INFO", "[kneron] first connect after server start — resetting device to clear stale model...")
+	//
+	// KL520 跳過 reset：KL520 是 USB Boot 裝置，reset 會退回 Loader 模式
+	// （firmware 從 RAM 清掉），然後需要重新載 firmware（~30 秒）+ USB
+	// 重新枚舉（~8 秒）。這讓原本 2 秒的 connect 變成 60+ 秒，而且
+	// Loader 模式的 connect_devices_without_check 不穩定（常需重試）。
+	//
+	// KL520 每次 connect 本來就是 clean state（RAM-based firmware，斷電
+	// 即清），不需要主動 reset 清 stale model。如果真的有殘留 model，
+	// 下次 load_model 前的 restartBridge 會處理。
+	//
+	// KL720 是 flash-based 裝置，firmware 和 model 會保留在 flash，reset
+	// 清 stale model 才有意義。
+	if needsReset && d.chipType == "KL720" {
+		d.driverLog("INFO", "[kneron] first connect after server start — resetting KL720 to clear stale model...")
 		if err := d.restartBridge(); err != nil {
 			d.driverLog("WARN", "[kneron] reset on connect failed (non-fatal): %v", err)
-			// Non-fatal: device is still connected, just might have stale model
 		} else {
 			d.driverLog("INFO", "[kneron] device reset complete — clean state ready")
 		}
+	} else if needsReset {
+		d.driverLog("INFO", "[kneron] %s: skipping reset on first connect (USB Boot device, clean state by default)", d.chipType)
 	}
 
 	return nil