Aiming at the problem that UWB sensor measurement errors are caused by electrical conversion time delay and antenna delay in UWB technology, a UWB combined positioning algorithm based on graph optimization and EKF is proposed in this paper. Firstly, EKF algorithm is used to obtain the initial positioning value, and then the objective function including UWB ranging error is constructed. Then, the graph optimization algorithm was used to solve the base station location that minimized the overall location error of UWB in the whole positioning process. Then, the solved base station location was substituted into EKF algorithm for the second calculation to obtain more accurate location results. Finally, Mean-Shift algorithm was used to perform cluster analysis on the location results. Experimental results show that compared with the EKF algorithm and the least square method, the horizontal positioning accuracy of the proposed algorithm is improved by 27% and 38% on average, and the obtained target trajectory smoothness is much better than the traditional positioning algorithm.