Abstract: The platform frame is the framework of the track frame of the walking mechanism of the bulldozer and the key component of the ground support element.It mainly adopts the welded structure.Aiming at the problems of low efficiency and poor manufacturing accuracy of a certain type of bulldozer, the structural optimization design is carried out.The original two-stage square box structure is changed into three-stage crawler box structure.The new structure consists of front guide assembly, middle bending plate assembly, rear pivot box assembly, base plate, balance beam seat, trunnion, spring mounting seat, etc.The SYSWELD virtual simulation technology is used to model the optimized structure and simulate the post weld deformation, residual stress and structural strength under typical working conditions.The results show that the overall post weld deformation of the front guide assembly is 12.1 mm and the residual stress is 369.73 MPa.The structural stress of the bench frame structure is small under three working conditions: blade lifting, uniform speed retreat and obstacle retreat.The stress value is large under the two working conditions of eccentric load at the left knife angle and maximum traction retreat, but it does not exceed the yield strength of the base metal.At the same time, the optimized structure reduces the weight, simplifies the assembly and improves the safety factor.Finally, the physical prototype is adopted for verification, the process flow is convenient, and the product reliability is guaranteed and improved.Highlights:(1)The three-stage caterpillar box frame was first applied in the new product of bulldozer, which solved the problems of low production efficiency, insufficient structure technology and poor manufacturing accuracy consistency of the original structure.(2)Virtual simulation technology goes deep from R & D to manufacturing process, and realizes iterative simulation of data.It is the first typical case to effectively guide the optimization of product structure and manufacturing practice.(3)This paper combines theory with practice, analyzes and verifies the R & D and manufacturing process from the whole process, and provides a new idea reference for the introduction of methodology into enterprise production process.