Aiming at the damping and vibration isolation needs for high-speed rotor-bearing system, a variable structure damper was proposed, of which the stiffness and damping coefficients are not constant, but time-varying functions triggered by environmental events. The variable structure principles of stiffness components and damping elements in this new damper were analyzed. The mathematics and mechanics model of a single component were developed. The changing relationship of components critical mechanical parameters (stiffness and damping coefficients) with environmental factors was researched, and its movement and forces were analyzed. The four kinds of dampers were obtained to the point of function matching through the assembly of different parameters, wherein three kinds of variable structure damper. The impact of different preset forces, fluid temperature and structural parameters in two throttle type of pores and capillary on stiffness and damping coefficients of damping was analyzed. A traffic model of atypical hole throttling form was obtained through experimental modeling. About the three kinds of variable structure damper, its applications in engineering were explored from function features, application objects, working conditions, installation and arrangement way. This study provided a theoretical support for the development and application of the low failure probability and high reliability variable structure damper.