Abstract: Aiming at problem that the low positioning precision in wireless sensor networks, this paper proposed an improved weighted centroid localization correction algorithm based on virtual beacon nodes(IWLCA-VBN). On the basis of calculating the distances between unknown nodes and beacon nodes, the algorithm selected some virtual beacon nodes to help positioning. The algorithm got the weighted formula by the theory that the positioning had the least error when the triangle was trilaterally equal and consisted of three beacon nodes which can communicated with the unknown nodes, then the coordinates of the centroid of the suitable triangles were located through centroid localization algorithm and the initial coordinates of unknown nodes were calculated by weighted centroid localization algorithm. The two positioning nodes whose distances were the nearest to the initial coordinates were selected as the reference nodes to make the final coordinates of unknown nodes more accurate. The simulation experiments show that the algorithm can effectively reduce positioning errors, and it can get higher positioning accuracy.