Abstract: The microgravity simulation on the ground is an important step to improve the on-orbit reliability of spacecraft. The low-stiffness suspension device is usually employed in the microgravity simulation, which results in the low bearing capacity of the device and the interference from the device's vibration. With this problem in mind, a quasi-zero-stiffness suspension device with consideration of its own vibration is designed in this paper. Firstly, the expression for the frequency of the bearing spring is derived by ignoring secondary factors. The conditions for the main parameters are discussed in a principle analysis. After that, a design procedure is proposed according to the payload mass and the displacement in the experiment. A quasi-zero-stiffness suspension device is thus designed, that can adjust the equilibrium position and the geometry parameter. A static testing and a vibration isolation experiment using the suspension device are conducted. It is shown that with this suspension device, the quasi-zero-stiffness and a high bearing capacity can be secured, and the interference from its vibration can be eliminated.