Abstract: Combining advantages of classical time synchronization algorithm TPSN and RBS, a new energy-efficient and high-accuracy algorithm RBTP was proposed. The algorithm utilizes character of broadcast in wireless communication and adopts the maximum likelihood estimation and the least square algorithm to calculate clock offset and clock skew, then uses the results to compensate the clock. The simulation results show that RBTP algorithm reduces energy consumption compared with TPSN and RBS algorithm, improves synchronization precision, and it can meet the needs of underground grid fault location system for time synchronization.