Movable power station is an emergency power supply (EPS) equipment. It consists mainly of a diesel generator and a noise reduction package. The noise reduction package has been designed by empirical methods traditionally, which usually leads to underdesign or overdesign. This paper aims to investigate the strength, stiffness and frequency characteristics of the package by finite element method, thus structural optimization scheme of the package is further obtained. The optimum package proved to be in good performance compared with the original structure.