This paper proposes a method for real-time reporting of low-voltage residential users' power outage events based on dual-mode communication unit (micropower wireless communication unit and narrowband carrier communication unit). Through the hardware circuit modification of the communication unit installed in the smart electricity meter, the expansion of the power user electric energy data acquisition system communication protocol, and the upgrade of the software of electric energy data acquisition device, in the event of a power failure, the communication unit immediately generates a power failure event and actively reports it. This paper also proposes an reporting strategy about anti-false alarm and anti-collision, to ensure the effectiveness of single and transformer area blackout reporting, thereby realizing the active repair of power failure and improving the power supply service level.