Abstract: The study proposed a new weighted least-square method and it is introduced to the localization process of sensor networks. DV-HOP algorithm can be improved based on this novel method. In this paper, the matrix condition number is introduced to adjust the weight of several functional in weighted least-square method. The coefficients are decided in a nonlinear optimization problem and it is difficult to get the best solution. A second best solution can be obtained easily by our method. The method is applied to solve two-dimensional Poisson problems and the results show it is valuable and is advantageous to similar problems. Efficiency and stability of the algorithm is proved in several numerical examples. The simulation results show that the proposed improvements can greatly enhance the localization accuracy of the nodes.