The tracking errors of large-caliber optical telescope in the process of observing astral target consists of telescope tracking jitter error which is mainly caused by wind-load, and wave-front tilt error caused by atmospheric turbulence. A simplified model concerning telescope tracking error is established, and a new kind of algorithm based on AR model to separate the telescope tracking jitter error from the tracking error caused by atmospheric turbulence is proposed. Finally, an experiment is conducted on the platform of the 1.8 M telescope in Gaomeigu Observing Station to test this algorithm. Experimental results show that the telescope tracking jitter error caused by wind-load is directly related to the direction and speed of the wind, which conforms to the theoretical analysis.