The ASRTU Micro-satellite is a 12U CubeSat managed by Harbin Institute of Technology. In order to meet the needs of ASRTU micro-satellite mission, a health management method suitable for this mission is proposed for the attitude control system. Firstly, according to the main performance indicators of the ASRTU micro-satellite attitude control system, the configuration of sensors and actuators and the attitude operation mode are designed. And the system-level health management strategy is given according to the priority order design of the sensor. Secondly, the equipment-level health management strategy is formed based on the output data. And a cross-detection strategy for the magnetic torquer utilizing multiple data and extended state observer was designed. Finally, three types of faults are set for the star sensor to simulate and verify the proposed health management strategy.