Abstract: SF₆ high voltage circuit breaker, composing of two core components, namely arc quenching chamber and spring operating mechanism, is the most important control and protective equipment in power transmission system. The motion of arc quenching chamber is driven by spring operating mechanism. In order to investigate further, the following study is conducted concerning the puffer SF₆ high voltage circuit breaker. The dynamic mathematical models for arc quenching chamber and spring operating mechanism are established based on the law of energy conservation. The mathematical models of puffer chamber pressure and buffer force is built and studied. The virtual prototype model of circuit breaker is obtained by co-simulation of ADAMS and Matlab. The mechanical displacement characteristics of circuit breaker are simulated, the dynamic force and structural optimum design of parts are calculated and analyzed. The simulation and experimental curves of mechanical displacement characteristics of circuit breaker, which can verify the accuracy of the simulation, is compared and contrasted.