Abstract: The piezoelectric actuator was designed and developed on the basis of the structural characteristics of the piezoelectric stack. The optimal preloading force of the piezoelectric actuator was determined. The piezoelectric actuator with the preloading force was connected with inertia mass block to form an inertial piezoelectric actuator. The vibration reduction effect of the inertial piezoelectric actuator was studied. The results show that the optimal preloading force of the piezoelectric actuator was 225 N, and the corresponding maximum output displacement was 10.35 μm. The vibration reduction test device with the maximum output displacement of the piezoelectric actuator of 10.35 μm and the mass of the inertial mass block of 130 g, the inertial piezoelectric actuator had good vibration reduction effect when the vibration frequency were 50, 75, 100 Hz.