This paper researched on the attitude control of Micro-satellite using only magnetic torque for the different control modes including detumbling and attitude acquisition as well as threeaxis stabilization. The satellite model was established relative to orbit frame firstly, then based on the energy considerations and Lyapunov stability analysis methods, the B-dot controller for detumbling was presented, moreover, a new method using global energy control for attitude acquisition and three-axis attitude stabilization was given. At the same time based on the Linearizatlon of the satellite model, a constant gain LQG-controller was designed. Simulating result indicated that the B-dot controller can detumble the satellite's rate effectively; the global energy controller may be used in the large range of attitude capture and stabilization modes; while in small angle range the LQG controller has high precision but the stability properties is not so good compared to the energy controller.