On the basis of experiments on force-speed characteristics of solenoid valve damper, a slide model control strategy based on saturated input was put forward for a quarter vehicle semi-active suspension with solenoid valve damper, which considered the nonlinear properties of vehicle semi-active suspension and output saturation properties of solenoid valve damper with adjustable damping force. A quarter vehicle nonlinear model with semi-active suspension and a suspension reference model with simplified input were built. A slide model controller was designed for a quarter vehicle nonlinear model. Meanwhile, considering the damping force output saturation property of solenoid valve damper, an assistant analysis system was designed to generate control compensation signal in order to compensate the saturation of the slide model controller. The results of simulation under Matlab/Simulink and experiments showed that the slide model controller based on saturated input could effectively eliminate the influence of output saturation of solenoid valve damper, and make the performance indexes, such as vehicle body vertical acceleration and suspension working space, close to the corresponding ideal output of a suspension reference model. It could also optimize the semi-active suspension design and control so as to improve vehicle ride comfort.