Abstract: Personnel trajectory playback is an important function of the precise positioning system for underground personnel in coal mines. Aiming at the huge amount of data in the precise positioning system of coal mines, which leads to problems such as long calculation time or the use of card readers for trajectory playback, a four extreme values trajectory playback method for the precise positioning system of coal mine personnel is proposed. This method is based on UWB (Ultra Wide Band) precise data and GIS (Geographic Information System) map, considering the different ways of people passing through the card reader, the four extreme values extraction algorithm is used to extract four key data points, namely the maximum on the left, the minimum on the left, the maximum on the right and the minimum on the right, and the trajectory playback methods are compared. Compared with methods such as full data calculation and regional data calculation, the four extreme values trajectory playback method has the characteristics of fast calculation speed and accurate trajectory.