The two-axis two-gimbal airborne photoelectric stabilized platform is widely used in small carrier because of its simple mechanism,low cost and small size.There is a complex nonlinear coupling between the carrier and the electro-optical platform as well as between the platform frames.Based on kinematics and dynamics,the mathematical model of coupling torque was established by the means of mechanism modeling and the dynamic characteristics were simulated in various states.Simulation results show that when the frame is disturbed,the inner frame is more sensitive than the outer frame,and the inner frame recovered more quickly.The variation of angular velocity caused by angular velocity disturbance of airborne is smaller than that caused by frame torque disturbance.The coupling moment existed between the inner and outer frames when the airborne moved in three axes.At the same time,the control voltage is added to the inner frame motor,the coupling moment increased.