Aiming at the attitude control of unmanned underwater vehicle (UUV), a control moment gyros (CMGs) control system is designed based on ARM stm32f407, which owns many advantages such as large output torque and does not depend on fluid motion. Firstly, this paper briefly describes the system attitude control mechanism. Then the hardware design scheme is proposed with detailed design and type selection. Considering the requirements of the control task, the lower computer control program and the upper computer control interface are designed. Finally, the system is tested and verified by experiment. The results show that the designed system can effectively control the speed of execution motors, so as to output the required torque and meet the attitude control demand of UUV.