A star tracking control system based on twodegreeoffreedom piezoactuated fast steering mirror has been developed in order to suppress the influences of various dynamic interferences on the imaging quality of star observation system for astronomical telescope. On the basis of using feedforward control to compensate the hysteresis nonlinearity of piezoelectric actuator, the proportional integral differential (PID) feedback control is constructed to enhance the antiinterference ability of the system. The corresponding experimental system is set up to verify the effectiveness of the control system. The experimental results show that the maximum tracking error of astronomical telescope has been reduced by 78.3% by using the star tracking control system based on twodegreeoffreedom piezoelectricactuated fast steering mirror. The proposed star tracking control system can effectively enhance the imaging quality of the astronomical telescope.