Abstract: Based on the existing shape, position and contour dimensions of the melting welding and friction stir welding hook seat plates, the large cross-section and large thickness hook seat plate profiles were successfully developed by using the forward extrusion method with a large pre-charging extrusion machine (160MN). The large cross-section and large thickness hook seat plate profiles were tested for dimensions, chemical composition, mechanical properties, welding performance, fatigue performance, corrosion performance and microstructure. The performance of the large thickness hook seat plate profiles meets the requirements of TB/T-3260.4 for the corresponding thickness (t25-mm), and meets the requirements for batch industrial production and application. Compared with the mechanical properties of the melting welding hook seat plates, friction stir welding hook seat plates and large cross-section and large thickness hook seat plates, the large cross-section and large thickness hook seat plates formed by extrusion have a larger design redundancy, and the hook seat can be further thinned to achieve the maximum lightweight of the vehicle body.