Abstract: In order to suppress influence of the periodic interference signal’s fluctuation on the rotating telescope scanning system speed stability and imaging effect, the interference compensation control was carried out by establishing the interference torque model and error compensator. Firstly, it was obtained that the periods of the disturbances were time-varying but position-fixed through experiment. Secondly, by measuring the current of quadrature axis I_q, a set of disturbance torque model acquisition system based on Fourier theory was established, and the specific expression of the disturbance torque model was extracted through eight steps. Then, the periodic error was compensated according to the expressions through four steps. Finally, the effectiveness of control compensation was verified by the actual system. The experimental results show that angle error of the telescope can be reduced to less than ±5.5″ of the angle error every 10 ms when the telescope is running at the speed of 68 （°）/s, and the reduction amplitude is more than 30%, which can meet the requirement of ±7″, and the speed stability is greatly improved.