Abstract: A reliable data transmission protocol of wireless sensor network was proposed according to characteristics of data flow of coal mine wireless sensor network, which was based on position information of sensor nodes and integrated MAC and routing. The protocol uses probabilistic awakening work mode, and selects forwarding node according to connectivity of local node, dump energy of the node and occurrence probability of regional event. Meanwhile, the protocol introduces standby node to forward data when main node is invalid, so as to ensure reliable data transmission. The simulation results show that the protocol reduces energy consumption of node in wireless sensor network and improves real-time performance of data transmission as well as reliability.