Abstract:Due to the capability of sailing in both water and air, underwater-aerial cross-domain vehicles has maintained high research interest in recent years. The vehicle requires entering and exiting the water autonomously, which results in the bionic research on some animals which can cross the water-air interface and move in two mediums has also become the focus of continuous attention. Flexible material is in accord with the conformation of some creatures more, and flexible wing resolves some problems which exist in the rigid wing, for which flexible winged bionic underwater-aerial cross-domain vehicles has broad research prospect. It is briefly introduced that the research on rigid winged bionic underwater-aerial cross-domain vehicles, and focus on the research about flexible winged bionic underwater-aerial cross-domain vehicles, and the difficulties that may arise in the development process of the current flexible winged bionic underwater-aerial cross-domain vehicles are discussed.