With the advances in image-guided weapons, it is quite necessary to develop a real-time digital scene simulator system that can test in laboratory the guiding information processing machine. A real-time digital scene simulator system, composed of a high performance PC machine and a PCI card, is introduced in this paper. Especially, the work flow and structure of the simulator system, together with the principles and implementing methods of the system software and hardware, are described in detail. Finally, the experimental results indicate that the system can meet the requirements of practical applications.