Abstract: Coal mines often adopt the KJ251 emergency rescue personnel positioning system. To ad⁃ dress the problems such as small signal coverage area，weak positioning signal，poor real-time perfor⁃ mance and lack of video monitoring function of the system，the issues existing in the personnel positioning system are analyzed from aspects such as positioning signal coverage，positioning accuracy and system functions. According to the actual needs underground，a rescue personnel positioning and video monitoring system based on wireless local area network data transmission technology was designed. This system utiliz⁃ es industrial ethernet for data transmission，underground video system collection，multi-base station data collection，and control by the ground centralized control station，thereby achieving functions such as under⁃ ground personnel location and three-dimensional picture display.The system also features personnel posi⁃ tioning trajectory query，real-time positioning，report storage query，multi-directional communication，hu⁃ man-machine interaction，and 3D animation imaging，among other advantages.Through the practical appli⁃ cation effect in Xiaoyu Coal Mine，it can be known that the personnel positioning error is controlled within 0.5~1.5 m，the positioning time is shortened to 2.4 s，the system failure rate is reduced to 5.2%，the annual maintenance cost of the system is reduced to 17 000 yuan，and the coverage radius of personnel position⁃ ing at a single base station is expanded to 320 m，which greatly improves the efficiency of emergency res⁃ cue in coal mines. Remarkable application results have been achieved.

Key words: coal mine, emergency rescue, personnel positioning, video monitoring