Abstract: Due to the low localization accuracy of the DV-Hop localization algorithm, this paper proposed an improved DV-Hop localization algorithm based on secondary correction error(Secondary Correction Error DV-Hop, SCEDV-Hop). Firstly, multi communication radius is adopted in SCEDV-Hop to refine the hop value between nodes. Moreover, orthogonal polynomial fitting method, a mathematical model, is taken advantage of to correct the distance error. Then subtraction first and then square, a strategy, is introduced to solve the equations. At the same time, the distance and distance error are taken as weighting factors to construct the weighted matrix to solve the unknown node coordinates. Finally, the redundant information obtained by solving the equations is employed to refine the coordinates of unknown nodes. Simulation experiment result showed that the SCEDV-Hop can effectively decrease positioning error and increase the positioning accuracy.