When RSSI is used to locate unknown node of wireless sensor network, the RSSI values are easily affected by environment will cause location error. Thus, quadrilateral weighted centroid localization algorithm based on range correction of RSSI ( QWCRC) is proposed. Firstly, the optimized RSSI value is obtained by Kalman filtering of the received RSSI values, which makes the ranging as close as possible to the real distance. Secondly, location of unknown node is determined by quadrilateral weighted centroid localization algorithm, at the same time, the method of least squares is used for auxiliary positioning. A new solution is provided by the algorithm to the case where the adjacent anchor node circle does not intersect. Finally, the experimental results show that compared with the quadrilateral weighted centroid algorithm ( QWC) and the triangle weighted algorithm modified by RSSI ranging ( TWCRC), the positioning accuracy of the improved algorithm can be improved by 87. 14% and 35. 51% respectively when the number of anchor nodes is 5×5 and the noise intensity is 0 dbm.