To address the problem that anchor ratio has a strong impact on localization error and coverage in Euclidean algorithm, this paper proposes an improved distributed localization algorithm. This method uses high localization accuracy nodes as new anchor nodes. According to the information, other nodes raise the localization accuracy by iterative refinements. And it controls the circulation times with the variance of coordinates. Simulation results show that, compared with Euclidean algorithm, improved localization algorithm can enhance the localization accuracy efficiently when the anchor ratio ...