In order to solve the problem that the tracking accuracy is reduced or even the target is lost due to the deviation of angles-only measurement information during the tracking process， a method is proposed for space non-cooperative target tracking based on relative distance estimation in geostationary orbit. First， the main spacecraft coordinate system is taken as a reference， and the relative motion model of space non-cooperative target is established. Second， the tracking equation is established based on Clohessy-Wiltshire （C-W） equation. Third， the relative distance is normalized as the unit quantity， and the difficult-to-observe relative distance is converted into the ratio of speed to distance. And the coordinates of the space target are used to estimate the radial component. Thereby， the relative motion trajectory of the space non-cooperative target can be obtained. Finally， the algorithm is simulated and verified， and the deviation angle between the actual motion trajectory and the predicted motion trajectory of the space target is used as the result. The simulation results show that， compared with the traditional algorithm， the tracking algorithm can obtain a higher-precision motion trajectory and has better robustness. The algorithm can be easily implemented in engineering.