In this paper, we propose a space-air-ground integrated electric power emergency communication system based on BeiDou Navigation Satellite System (BDS) and low earth orbit (LEO) satellite. Specifically, we assume that power communication systems are disabled after natural disasters and cannot communicate with the outside world without timely post-disaster power recovery. Based on the existing precise positioning and short message function of BDS, we build a novel space-air-ground integrated network for data fusion and traffic relay with LEO satellite, hot air balloon and Unmanned Aerial Vehicle (UAV). The new electric power emergency communication system can provide precise positioning, transmission of dispatching commands and observation of post-disaster video in the case of power communication network paralysis, which solves the bottleneck problem of existing satellite power emergency communication system.