With continuous expansion of manufacturing scale, the scene data that virtual prototype system has to deal with is far beyond a single computer's processing power. To meet the requirements of large-scale simulation, this study designs a virtual prototype system based on PC cluster. The problems including software architecture of virtual prototype system, transformation of CAD model, scene graph management, real-time rendering of huge dataset, and so on are investigated in detail in this paper. Finally a prototype system has been implemented. The system is constructed by PC cluster and gigabit LAN. The aim of the system is to build a large-scale, high resolution, immersive virtual environment supporting users' virtual design and manufacture.