The actuator is one of the important subsystems that constitute the Active Control of Structural Response (ACSR) system of helicopters. Variable Sliding Mode Sliding Mode Control (VSMSMC) is proposed for achieving the simultaneous tracking of harmonic force amplitude, phase, and frequency, and precision in centrifugal harmonic force generator system. First, harmonic force equation and the Permanent Magnet Synchronous Motor (PMSM) dynamic equation which contains uncertainty factors such as parameter variations, external disturbances, and linear friction are established according to the principle of centrifugal harmonic force generator. Then, by analyzing the control principle of harmonic force and combining the characteristics of SMC, the expectation phase of the centrifugal harmonic force generator is introduced into the sliding mode equation of the SMC, and the VSMSMC is designed base on PMSM. Furthermore, the Lyapunov function is used to prove the accessibility and the stability of the VSMSMC. Finally, the performance of the VSMSMC is verified by simulation in MATLAB/Simulink. Compared with the existing method, the VSMSMC can track the amplitude, phase, and frequency of the desired harmonic force and leads to higher tracking accuracy and higher tracking speed when the centrifugal actuator starts. © 2019, Press of Chinese Journal of Aeronautics. All right reserved.