Abstract: Based on analysis of different properties and application status of mainstream proximity detection methods for machines in coal mine, a novel proximity detection method using high wireless precision ranging and three-dimensional location technology was proposed. The method uses wireless distance measurement method SDS-TW-TOA to measure distance between personal tag and detector, calculates precise coordinates of personal tag relative to mobile device through three-dimensional least squares method, and finally obtains detection result through regional setting and judgment. Field test results show that the proposed method can achieve 360° detection around the equipment, and has characteristics of high positioning accuracy, short response time and convenient configuration compared with RSSI method and magnetic field marker method.