As a key component of DC medium voltage breaker, the switch mechanism is required to open in high-speed and can withstand the breaking voltage which is generated during opening motion. Thus, the design of driving circuit of switch mechanism is very important to optimize the mechanism structure and improve mechanism opening characteristics. First the motion principle of high-speed switch was given in this paper, and the influence of driving circuit parameters on mechanism opening characteristics was analyzed. Then two driving circuit solutions were provided with simulation and test verification analysis. Finally, the prototype was built according to aforesaid analysis. The design of DC medium voltage breaker can be benefited by the research work in this paper.