According to the current topology maintenance algorithm is based on the topology reconstruction when the nodes movement, some nodes joining and exiting the network, node failure may cause the topology changes. This paper proposes a power control based on the topology maintenance algorithm PCTMA. PCTMA algorithm contains three mechanisms: Relay Node Selection Mechanism Based on Node Energy Consumption Model; Power Adjustment Prejudging Mechanism and Maintenance Mechanism Based on Event Triggering. Exploits the node energy consumption model to select the relay nodes and achieve the purpose of reduce the overall network energy consumption. Power Adjustment Prejudging Mechanism according to the relationships between the nodes transmit power and communication radius, the nodes maintain connectivity with each other based on the power control.The mechanism can prejudge how to adjuste the transmission power when the network topology changed.To deal with the different situation that causes the topology changes, the maintenance mechanism based on event triggering was proposed in the paper. The simulation results show that the PCTMA algorithm is superior to the XTC algorithm and NAPC algorithm in terms of average transmits power, network connectivity, and the number of live nodes in the network.