This paper presents a theoretic implementation method of Morphing Unmanned Submersible Aerial Vehicle(MUSAV),which can both submerge in the water and fly in the air.Two different shapes are put forward so that the vehicle can suit both submergence and flight,considering the tremendous differences between hydrodynamic configuration and aerodynamic configuration of a vehicle.The transition of the two shapes can be achieved by using morphing technology.The water-to-air process,including water-exit,morphing,take-off and steady flight,is analyzed.The hydrodynamic and aerodynamic model of the vehicle exiting the water surface obliquely and then taking off into the air has been founded.The control strategy after morphing is analyzed and the control method is given.Numerical method is used to validate the motion model of the water-exit process.Results of simulations show the validity of the proposed model and the feasibility of MUSAV in theory. This paper presents a theoretic implementation method of Morphing Unmanned Submersible Aerial Vehicle (MUSAV), which can both submerge in the water and fly in the air. Two different shapes are put forward so that the vehicle can suit both bottle submergence and flight, considering the tremendous differences between hydrodynamic configuration and aerodynamic configuration of a vehicle. The transition of the two shapes can be achieved by using morphing technology. The water-to-air process, including water-exit, morphing, take-off and steady flight, is analyzed. The hydrodynamic and aerodynamic model of the vehicle exiting the water surface obliquely and then taking off into the air has been established. The control strategy after morphing is analyzed and the control method is given. Numerical method is used to validate the motion model of the water -exit process. Results of simulations show the validity of the proposed model and the feasibility of MUSAV in theory.