GF-3 series satellites, the first C band and multi-polarization SAR satellite constellation in China, achieve breakthroughs in a number of core and key technologies. The distribution information architecture with two kinds of data buses is used for the satellite control, information transmission and management. In this article, the design of information system net architecture, function architecture, housekeeping data storage and playback flow, important data flow and payload data flow are described. According to the requirements of users’ convenience, a distribution and layered automatic mission management architecture is applied. It has a more advanced mission interface, in which way the satellite internal design can be shielded from the satellite user and it makes satellite used easily. To ensure the satellite operation stability in orbit, several automatic health management methods are used, including system monitoring, payload mission safety control, system recovery and reconfiguration, etc. Finally, the information system test matrices during developing phase and in orbit test results are described, and some suggestions for the following satellite information system design are put forwards.