In order to solve the issue of Some vehicle structure failure issue based on dragging to tray carriage load case, analysis the whole load case process. Infer the formula of the load case and obtain the key case. Taking advantage of explicit transient dynamic algorithm to simulation and resolve the typical load case. And the simulation result is completely consistent with the counterpart data from the test, which show that the mothed is effective. Based on the mothed, optimize the failure structure and realize them into the prototype, which is verified in the final test and it shows the design is effective. Realize the customization to generate simulation file automatically based on HYPERMESH secondary development TCL script, and improve modelling efficiency to at least 90%. The method in this paper can be an efficiency tool to develop vehicle body structure performance.