For low position precision of existing personnel positioning system of coal mine underground based on RFID, ZigBee, WiFi and so on, a precise positioning system of coal mine underground was proposed which combined visible light communication with inertial navigation system. In the system, underground LED lighting lamp is taken as LED visible light positioning base-station. Visible light signal is received by CMOS camera in intelligent information mining-lamp for positioning. Data of acceleration sensor and gyro in intelligent information mining-lamp is timely integrated to get moving track and direction of underground personnel. Data of inertial navigation system could be corrected through intelligent information mining-lamp identifying ID coding information of LED visible light positioning base-station for anew positioning, so as to realize precise positioning. Eight LED visible light positioning base-stations are arranged in coal mine underground. Positioning precision of the system is tested through five intelligent information mining-lamps moving at normal speed. The results show that positioning error of the system is less than 1 m, which meets precision requirements of personnel positioning in coal mine underground.