This thesis focuses on the impeller of a certain car water pump as the research object. Based on the measured point data, using the principle of NURBS surface formation, a 3D model of the water pump appliance is created by fitting the point. Based on the 3D CAD model of the water pump impeller, The CNC machining scheme of the water pump impeller is designed, simulating the tool path in the machining process, then obtaining the NC machining code. Based on the existing plate impeller and the design principle of parametric modelling, optimizing the geometric parameters of the existing water pump impeller blades and obtaining two new impeller structures. Using the FEM based on ANSYS software, analysing the strength and characteristics of these three different types of water pump impeller blades. The strength and stiffness of the impeller are researched, and verifying the rationality of the structure. A best comprehensive performance optimal impeller design model is obtained, which was used as a reference for optimization design.