This paper proposed the System in Package technology implementation about integrated electronic system in micro-satellite. Firstly, the composition of integrated electronic system in micro-satellite has been introduced. Then the necessity of System in Package application in micro-satellite has been proposed. The general extension module in the satellite-based electronic system has been realized through dividing the overall system into functional modules, then detailed design have been carried out about the module. After verification, all function have been realized. At the same time, the overall module weight have been reduced from 230 g to 48 g, and the volume has been reduced from 180 mm?130 mm?17 mm to 46 mm?46 mm?8 mm, which satisfies the requirements of miniaturization and lightweight design of the micro-satellite.