Abstract: Aiming at the requirement of high real-time and high precision personnel positioning in underground mine, the positioning algorithm of underground personnel based on ultra wide band (UWB) is studied. The double-sided two-way ranging (DS-TWR) mode is adopted to measure the distance between the positioning base station and the positioning tag. This mode does not need the clock synchronization of the positioning base station and the positioning tag system. Therefore, the positioning precision is improved from the source. According to the ranging information, the weighted least squares (WLS) algorithm and CHAN algorithm are used to estimate the coordinates of the positioning tag. The performance of the two algorithms is compared and analyzed through static and dynamic experiments. The positioning precision is comprehensively evaluated through the root mean square error and the cumulative distribution function (CDF) of the error. The experimental results show that in static experiment, the root mean square errors of CHAN algorithm and WLS algorithm are 5.878 6 cm and 8.007 4 cm respectively. The root mean square error of CHAN algorithm is 26.59% lower than that of WLS algorithm. In dynamic experiment, the root mean square errors of CHAN algorithm and WLS algorithm are 12.2923 cm and 21.1809 cm respectively. The root mean square error of CHAN algorithm is 41.97% lower than that of WLS algorithm. The positioning precision of CHAN algorithm is higher than that of WLS algorithm. And CHAN algorithm is more suitable for underground personnel positioning in coal mines.