Zoom system based on liquid crystal lenses can realize zoom without moving elements. This zoom working mode is applicable to some specific imaging systems, and has attracted much attention in recent years. The effects of liquid crystal lens parameters including zoom range and clear aperture on zooming performance of zoom system are studied. The calculation formulas of the maximum zoom ratio and the maximum field of view of the liquid crystal lens zoom system are theoretically obtained. According to the theoretically calculated structure, the zoom curve expression of the zoom system is obtained. The zoom curve shows that the zoom ratio grows faster and the focal length varies more sensitively when the system changes from short focus to long focus. Using the liquid crystal lenses developed by the University of Shanghai for Science and Technology, we design a Gauss model of liquid crystal lens zoom system with zoom ratio of 6 and full field of view of 60°. The design does not only verify the theoretical derivation, but can also be used as the initial structure of an actual liquid crystal lens zoom system.