Vibration capability and reliability is necessarily to be considered for electronic components design. In this paper, the vibration characteristics of electronic components were studied using FEM, for example, gridded electron gun. The dynamical mode of girded electron gun was established. Modal frequency and model obtained by simulation shows tendency as tested experiment results, verifying the correctness of the simulation model and method used. The Parameters showed an inherent property of structure, which provided a theoretical basis for production design, the optimization of parameters and the vibration-resistance reliability improvement of microwave tube. In the aspects of electronic components reliability analysis, the variations of production capability parameters under various stress environments can be gained by FEM simulation technology to evaluate environment adaptability and reliability.