The aerodynamic forces and moments acting on rotary wing air recovery UAV during wing rotation process represent strong nonlinearities, influencing the stability and safety of the air recovery process. In this paper, the dynamic modeling and lateral stability control of rotary wing UAV are studied. The dynamics model of the rotary wing UAV is established based on the Newton Euler method, and the additional forces and moments during wing rotation process are analyzed. Then the relationship between aerodynamic parameters and wing rotation angle is obtained through computational fluid dynamics, and dynamic response of UAV during wing rotation process are analyzed. The results show that the UAV cannot maintain a stable state during wing rotation process and lateral stability controllers based on active disturbance rejection control are designed and verified by simulation. The results of simulation show that the designed controllers can effectively solve the strong nonlinear and parameter time varying problems in the wing rotation process of rotary wing UAV, and ensure the stability of the wing rotation process of rotary wing UAV.