Abstract: For the positioning problem of vehicle in the occluded environment, a tightly coupled positioning method was proposed based on improved strong tracking filter for ultra wideband (UWB) and attitude and heading reference system (AHRS). In the method, the threshold was used to identify the UWB ranging anomaly value and eliminate its influence. A strong tracking filter (STF) algorithm was applied to the data fusion of the tightly coupled system, and the algorithm was improved by combining the positioning model to improve the stability of the algorithm and the estimation accuracy of the observed noise. The simulation and test results show that, the proposed method can provide accurate positioning information of vehicles in complex conditions. Compared with the single positioning of UWB and the use of several nonlinear filtering algorithms, the system has stronger robustness, higher positioning accuracy, and has strong practicality.