The long-term positioning accuracy of shearer independent positioning device is the key to intelligent coal mining. However, the state-of-the-art positioning accuracy of shearer is difficult to meet the demand of automatic mining. This article puts forward the coal mine working face end automatic calibration of inertial navigation positioning system, constructs the underground local positioning system based on UWB system, and calibrates the shearer position which can achieve the long-term autonomous cycle positioning of shearer. Considering the low positioning accuracy of the UWB system in the non-line of sight (NLOS) environment, the constrained square root unscented Kalman filter (CSRUKF) positioning algorithm is proposed. To further reduce the interference of NLOS error, the positioning results are optimized based on the velocity robust Taylor series (VRTS) algorithm with consideration of the motion speed to improve the final positioning accuracy. Based on the UWB positioning system and mobile platform, the simulated terminal positioning is conducted. Experimental results show that the CSRUKF-VRTS method is able to reduce the localization error and improve the positioning accuracy in the NLOS environment. The mean error of the x, y and z-axis is reduced from 0. 332, 0. 404 and 0. 306 m to 0. 266, 0. 212 and 0. 159 m, respectively. The corresponding average accuracy is improved by 17. 4% , 47. 5% , and 48. 1% , respectively. The proposed cyclic positioning strategy of coalmine working face end provides a novel idea for the long-term independent positioning and a reference for the positioning of NLOS environment.