Disclosed are a method and a system for remote wake-up and status check, with a wake-up signal generating unit generating and transmitting a wake-up signal to wake up an electricity supply unit of a remote device to operate normally and provide electricity for the remote device. The wake-up signal has an assigned electric voltage with specific characteristics for detection by the electricity supply unit while in power-off mode and, upon signal detection, the electricity supply unit wakes up to provide normal electric voltage output. The wake-up signal generating unit determines, according to an electric current on a wake-up signal feed line, whether the remote device is in an active mode. A low wake-up energy consumption enables system wake-up and a true powered-off sleep mode.