Abstract: Aiming at the problem of secondary impact caused by mismatching parameters of traditional isolation system with displacement restrictor, firstly, a mechanical model of the quasi-zero stiffness (MMPDQZS) isolation system was established by using the opposed disc spring as the negative stiffness component and the repulsive permanent magnets was used to adjust the nonlinear positive stiffness. The static characteristics of the system were analyzed. Then, the mathematical model of MMPDQZS isolation system was established. The influence law of different damping parameters on the impact isolation performance of MMPDQZS isolation system was analyzed. The impact characteristics were compared and analyzed through simulation and experimental study for without and with equivalent linear displacement restrictors and MMPDQZS limiters. The results show that for any initial clearance, there is an optimal viscous damping ratio that minimizes the system’s buffer coefficient. Smaller initial clearances generally lead to better impact isolation effects. Considering different initial clearance, the damping ratio of power-law fluid damping is 0.02, the velocity correlation index obtains the optimal buffer coefficient within the interval 2.2, 2.3, and the optimal initial clearance is when the clearance is equal to 4 mm. For any initial clearance, the buffer coefficient is proportional to coulomb damping, and smaller initial clearances result in better buffering performance. Compared with the equivalent linear limit isolation system, MMPDQZS limit isolation system can not only effectively limit the relative displacement, but also greatly reduce the buffer coefficient of the system and improve its impact resistance.