Abstract: Abstract: the fact that the location of personnel in coal mine is not precise, this paper studies the location and monitoring technology of underground personnel in wireless network based on ZigBee, and proposes a Trilateration- GSA algorithm based on RSSI to receive signal strength for precise location optimization. Through the platform of the ZigBee wireless network, getting the location information with multi group forecast multilateral location algorithm, and then through the gravitational search algorithm (GSA) for data optimization, so as to reduce the influence of special underground environment of location information, and then realize the precise location of underground personnel. Using maltab to simulate the environment of the coal mine and to carry out the simulation test, according the test data to error analysis, test results show that this algorithm can improve the accuracy of monitoring real-time location of underground personnel, provide technical support for underground personnel management, with good application value.