For a class of flexible skin morphing wing, this paper obtained the aerodynamic coefficients by wind tunnel combined with interpolation method, and established dynamics and kinematics models based on Newton Euler equations. According to the characteristics of the flight dynamics model and the control objective of the vehicle, we designed the integrated control law of lift and three-axis stabilization. Specifically, we applied the improved linear quadratic optimal control with extended integral state to the three loops of attitude as a whole. The velocity and position controller adopt the PID control, while the altitude control is realized by adjusting the pitch angle. Semi-physical simulation tests were carried out using speedgoat real-time simulator. Compared with traditional PID control, the experimental results show that the method proposed in this paper can effectively inhibit coupling phenomenon and uncertainty perturbation of the three attitude channels. Lift-to-drag ratio adjustment and attitude stability control can be achieved simultaneously through the cooperation of multiple servos.