The optimal design of vacuum switch is becoming an important research topic with the extensive application and increasing demands of vacuum switches. This paper analyzes the main elements of the vacuum switch design, and gives the design process of the vacuum switch. An optimal design method is proposed for the vacuum switch based on the concept and characteristics of virtual prototyping (VP) technology. By using computer aided design and the related software, we propose a method for vacuum switch modeling VP, the stress field VP of parts, the thermal field VP of electric heat, the electric field VP of insulation parts and the mechanical dynamic VP of kinematics system, which are integrated for optimization design for vacuum switches. This work is expected to provide a new idea for optimal and rapid design of vacuum switches.