In order to expand the application scope of folding wing UAV and extend the information acquisition ability of underwater platform,an underwater vehicle scheme of carrying UAV for dry launch was proposed by combining the advantages of UUV and UAV. In order to better evaluate the feasibility of launching UAV on the sea,the computational fluid dynamics simulation software StarCCM+was used to simulate the launching environment of UAV on the sea,and the floating and launching process of UAV was simulated in the simulation environment. The air-bag scheme and the propeller scheme were designed respectively by referencing foreign design experience,and the different sea-conditions,different structural-parameters and attitude parameters were simulated and evaluated,and finally the launching process was simulated under the sea conditions. The results show that the UAV carrier in the state of zero buoyancy underwater can float stably on the water surface under different sea-conditions by the air bag scheme and the propeller propulsion scheme. In terms of UAV launch,the difference between the maximum sinking distance of the air-bag scheme in still water and sea conditions is about 2.5%,and the consistency is better than the error level of the propeller scheme of 30%. The average maximum sinking-distance of the vehicle during the launch of UAV is 0.28 m,which is lower than 0.4 m of the propeller propulsion scheme. In a comprehensive comparison,the air-bag scheme is more stable and reliable.