A wireless communication device includes a Wi-Fi module for operating in WLAN system and a Bluetooth module for operating in Bluetooth system. After entering a power-saving mode, the wireless communication device is configured to turn off the Wi-Fi module and periodically scan an operational frequency band of a network using the Bluetooth module. When detecting a radio frequency signal having the same bandwidth as the network in the operational frequency band, the wireless communication device is configured to enter a normal mode.