To solve the problem of spacecraft power supply and distribution system weight and volume constraints, and to increase the proportion of effective load, using a miniaturization intelligent distribution solution which chooses single chip microcomputer (SCM) as the core processor, solid state power controller (SSPC) for power output devices, RS422 data bus to data transmitting. In place of the traditional design using relay and breaker as power output device and cable as Instruction transmission medium, the design realizes reliable power supply and distribution of electric load of spacecraft. It can not only effectively reduce the weight and volume of the instrument and equipment on the spacecraft, but also improve the working reliability and data transmission rate of power supply and distribution system, and achieved remarkable results in fault isolation, surge suppression and other important functions of the power supply and distribution system. It also has a referential significance to other spacecraft electrical system design.