Abstract: Aiming at the problems such as unreasonable model node, poor positioning accuracy, unstable algorithm and so on existing in positioning of wireless sensor networks in underground coal mines, the paper proposed a new model of node in underground workings, put forward node 3D positioning algorithm based on particle swarm algorithm for wireless sensor network in coal mines. This algorithm makes the mean square error of the estimate and the measured distance between the unknown node and the adjacent anchor nodes in three dimensional space as the optimization objective function. The positioning accuracy is improved through particle swarm optimization. The theoretical analysis and simulation results show that the algorithm has higher positioning accuracy and good stability, suitable for wireless sensor network node localization in underground coal mine.