Abstract: Aiming at personnel and equipment locating problem in one-dimensional environment of underground coal mine, we studied one-dimensional positioning theory and application. We propose one-dimensional piecewise positioning method and designed the positioning system based on radio frequency（RF）module. The system takes ATmega1284P microprocessor as the controller and the nanoPAN5375 as the RF chip, and uses symmetrical double-sided two-way ranging method to achieve real-time ranging, and adopts one-dimensional piecewise positioning method and Kalman filtering algorithm to calculate the final location information. The results indicate that the system can perform real-time ranging and positioning and the positioning error is less than 1 m.