High-precision airborne laser pointer is a tri-axis operating system. Based on the Lagrange theorem

the tri-axis

coupling

nonlinear dynamics model is derived

and by analyzing the velocity coupling and the dynamics coupling relationships among axis of the frames deduces their analytical relationships in theory. According to the electrics and mechanics equations of the actuator-torque motor

the open-loop transfer function matrix of the control variable is established

and next a cascade compensator is designed to decouple the control system. After decoupling

another compensator is cascaded to the system to satisfy the quick-response requirement

also the system is stable at the same time. At last

the electro-mechanical model is verified by computer simulation

and sets a foundation and provides theoretical references for further research and design of the control system of the high-precision airborne laser pointer.