Localization of nodes is an important application of wireless sensor networks. In order to restrain the influence from manifold environment factors that existed in practical application to WSN node positioning accuracy, a location algorithm based on error correction is presented. The particle swarm optimization-received signal strength indication (PSO-RSSI) based on particle swarm optimization (PSO) is used to optimize a number of link quality indication (LQI) (exist some deviation) that unknown node receives from sink node. Then LQI is transformed to RSSI to get distance. The result of the experiment shows that this algorithm can improve positioning accuracy and it has general application significance.