Abstract: The smallscale agile satellite using single gimbal control moment gyroscope(SGCMG) as the actuator has singular state that obstructs continuous changes of the total angular momentum vector during the attitude maneuver. This paper transforms the singular problem into a dynamic control problem with state constraints in the view of overall attitude control system. The implementation of singular circumvention is based on control variable parameterization(CVP) method to obtain an optimal trajectory. This algorithm divides gimbal angular speed programming into piecewise linear in the largeangle attitude maneuver task. There is no complicated requirement for the algorithm design of the gimbal servo system. It results in benefit of resources saving that simple acceleration and deceleration control is implemented on gimbal system. In the process of trajectory planning, the constraints in engineering are taken into consideration. An optimal trajectory that comprehensively considers energy resources and target accuracy can be planned according to the requirements of the attitude maneuver task. The simulation results show that the algorithm achieves a gentle change of the attitude parameters and the satellite angular velocity trajectory. The maneuvering error is in the order of 1×10-3. The satellite runs stably and SGCMG does not have singularity during the maneuvering process.