Abstract: Amphibious aircraft studies are inadequate in domestic. Systematic technical guidance is insufficient regarding the high-lift devices of amphibious airplane. In order to grasp the basic principle and design technology for the high-lift devices of amphibious aircraft, which satisfy the aerodynamic and hydrodynamic design requirement, special design methods have been systematically investigated in this paper. Technical characteristics and design features are compared between amphibious aircraft and land-based aircraft based on domestic and international high-lift device types and design features. On the basis of the special operating environment, operating mode, and hydrodynamic characteristics of amphibious aircraft, various factors affecting the designing of high-lift devices of amphibious aircraft are discussed for the first time. These factors include splash, wave-resistance, and so forth. The high-lift device designs for amphibious aircraft should meet the general design principles of land-based aircraft, and satisfy the special technical requirement of aquatic environment and operating mode. The aerodynamic configuration of amphibious aircraft is closely related to hydrodynamic configuration. The design of high-lift devices for amphibious aircraft is significant different from that for land-based aircrafts. The main sensitive parameters in the design progress of high lift system are pointed out, and the correlation is discussed between trailing-edge high-lift devices design and anti-waves capability. Finally, some suggestions are given for the design principles of the high-lift devices of amphibious aircraft.Based on a lot of water/wind tunnel tests and CFD results of hydrodynamic/aerodynamic characteristics one high performance flap scheme of a civil large amphibian aircraft has been developed according to the present design principle.A water tunnel test shows that, there is no splash on the high-lift devices, and the airplane has the ability in resisting given height wave. This design is completed by solving the contradiction between aerodynamic configuration and hydrodynamic configuration.The design principle of high-lift devices for amphibious aircraft summarized in this paper is feasible, and has a high application worth. Moreover, it can be used as a reference material of the amphibious aircraft high-lift devices design.