Abstract: For complex underground environment,this article uses wireless sensor network location algorithm based on range-free to realize underground personnel location.In order to achieve accurate location,the paper adopts location algorithm based on two mobile anchor nodes.Through the shortest path among the three nodes to determine a straight line to minimize the error of location nodes,and at the same time,it can avoid the error of the nodes location caused by obstacles or other factors,and improve location accuracy maximumly.The simulation show that the precision of the nodes location are concerned with the cylinder number of two mobile anchor nodes and the round divided,the more of the cylinder number and the round divided,the higher of the precision of node location.