The high pressure common rail injection System is one of the most advanced technologies for the diesel engine to reduce fuel consumption exhaust emissions. While the design of the high pressure common rail injector is the key for the whole system. Considering that the working pressure of fuel in the injector, a more accurate injector body model was established with the modeling software Pro/Engineer in this study. Finite element analysis technology in Ansys software was applied to calculate the strength of injector body of the high pressure common rail system under different injection pressures. And then the rationality of structure parameters and material selection of the injector body can be analyzed and verified. The research conclusions can provide the theoretical basis for the optimization design of the injector.