Abstract: In view of problem of big error existed in current location method of coal mine detonated source (electric spark source) adopting two-dimension weighted centroid localization algorithm, an improved three-dimension weighted centroid localization algorithm was proposed. RSSI propagation model in free space is established according to the characteristics of electromagnetic wave generated by electric spark in the surrounding space, and the Gaussian model is used to correct the RSSI value, so as to obtain more accurate distance; in the three-dimensional space, detection node is selected and the weighting factor index k is introduced, and coordinates of target node is determined in order to realize positioning of electric spark source. The simulation test results show that the algorithm has high positioning accuracy, and the maximum position error is 0.319 m, the average error is 0.265 m.