The paper describes the details of a new kind of 3-axis air bearing test bed based on variable-speed control moment gyro for satellite attitude determination and control system simulation. The base of the test bed is a 3-axis air bearing platform newly developed by CIOMP. The main actuator of the system is a cluster of four variable speed control moment gyros constructed in pyramid mounting arrangement. The system also includes six gas thrusters to assist VSCMGs avoid singularity. The attitude determination system is also introduced which consists of three fiber optical gyros

a horizon sensor and a magnetometer. The details of main parameters of all parts and analysis of them are given to illustrate the platform can be used in the simulation and validation of many algorithms for modern agile small satellite. It can be used for reference by other facilities in this research field.