In order to solve the problems of low positioning accuracy and poor continuity in the single navigation source positioning system in indoor and outdoor seamless positioning, a GNSS/UWB/IMU integrated indoor and outdoor seamless navigation and posi-tioning algorithm based on robust estimation was proposed. In the face of complex indoor and outdoor scene switching, the robustness estimation algorithm is used to evaluate the confidence level of the two observation signals collected by GNSS and UWB and fuse them, and the fused data is used as the new observation value, and the extended Kalman filter algorithm is used to fuse the new observation value with the data of the inertial system to achieve fusion positioning. In order to evaluate the navi-gation and positioning accuracy of the algorithm in the presence of interference and noise, the inertial navigation positioning module, the satellite positioning module and the ultra-wideband tag were integrated together and field tests were carried out. Experiments show that the root mean square error of the proposed fusion positioning method is 6.40cm in the east direction and 6.73cm in the north direction, and the maximum error is not more than 28.55cm.