In order to optimize the design parameters of the quasizerostiffness vibration isolator, the mathematic model of quasizerostiffness was established to determine the relationship between the parameters of the isolator and the mathematical model of quasizerostiffness was simplified. The influence of the parameters of the vibration isolator on the static characteristics was analyzed by the thirdorder Taylor formula. The dynamic characteristics of the vibration isolator were analyzed by the harmonic balance method. The relationship between the vibration frequency with the vibration amplitude or the force transmission rate was obtained. The influence of the parameters on the vibration amplitude and the force transmission rate was analyzed. The results show that the low frequency performance of the kinetic characteristics can be improved by setting the parameters reasonably.