In this paper, a friction compensating method based on data fusion in telescope controller is proposed to enhance the tracking precision of telescope systems. Telescope systems usually suffer some uncertain disturbances, such as friction, wind loads and other unknown disturbances. Especially, when telescope change speed direction, the friction is the dominate track error. Thereby, to ensure the tracking precision, the friction compensating method which can attenuate the influence of friction is introduced. Besides, to improve the friction identify accuracy, a data fusion method which fuse accelerometer and encoder is adopted. Finally, a few comparative experimental results show that the proposed control method has excellent performance for reducing the tracking error of telescope system.