Abstract: The energy model of the Wireless Sensor Networks (WSN) is constructed in this paper combined with the application of the WSN in smart grid.This paper also analyzes the principle as well as the implementation method of the LEACH algorithm.In consideration of the characteristics of power communication,it points out the weakness of the LEACH algorithm and proposes another modified SG-LEACH algorithm,which divides the node into ordinary node and senior node,and the senior node can be elected as cluster head nodes with higher priority.The simulation results show that the SG-LEACH algorithm can effectively balance the node energy consumption distribution,significantly extend node survival time,and improve the transmission efficiency of the network.