Positioning technology is one of the key technologies of wireless sensor networks（WSNs）.Aiming at the defect that classical distance vector hop（DV-Hop） algorithm has low positioning precision

an improved algorithm is proposed.The hop count is corrected by correction factor to determine the optimal hop count. The first-order partial derivative is obtained by using the average hop distance between anchor node and unknown node to obtain exact distance. Node coordinate calculation uses the improved weighted least squares method. The simulation results show that the improved DV-Hop algorithm reduces the node positioning error and improves the positioning precision.