An improved DV-Hop algorithm based on hop-count calculation， hop-distance estimation and coordinate estimation algorithm is proposed. Firstly， the hop number is optimized by the multi communication radius. Then the average hop distance is modified by the weighting method， and then the received signal strength indicator （RSSI） ranging technology is used to define the average hop distance error to achieve the second correction. Finally， there is a need to eliminate the heteroscedasticity of the error term and further reduce the error by the weighted least square method. The simulation results indicate that the improved algorithm can reduce the positioning error while maintaining a small time complexity.