Satellite simulation technology is an effective method to reduce the risk of satellite system application and the production cost. With the satellite electronic system tending to integration and comprehension, it is particularly necessary to do researches on simulation of the satellite integrated electronic system (IES). The paper explains the design ideology of IES digital simulation, builds a simulation framework, introduces the realization of the digital simulation of IES, and develops universal and authentic simulation software. In simulation application level, the paper realizes the function of the real satellite IES and the software has been applied to real satellite testing system.