A design scheme of intelligent, non-contact and flexible small unmanned surface vehicles (USVs) for bathymetric survey in shallow waters such as reservoirs and lakes is proposed. The mechanical structure of the hull, the measuring device, the core control cabin and the power plant are designed, and the water depth measurement tests of the prototype indoor pool and outdoor lake are carried out. The test results show that the USV can move between the set path points through GPS navigation, accurately measure and upload the water depth information, and has the characteristics of simple structure and flexibility, and has certain practical value and market prospects.