According to the result of noise and vibration test of a fuel cell veh icle while hydrogen auxiliary system operated independently, it was confirmed th at an improper structure of hydrogen auxiliary system cabinet led to greater noi se and vibration both inside and outside of the vehicle. In order to check the e xistence of the resonance frequency and to optimize the structure of cabinet, a modal test and a finite modal analysis were carried out for the cabinet, which s howed that the cabinet had a mode which was multiple of fundamental frequency of the vibration source, and the resonance occurred while the hydrogen pump operat ing. Based on the cabinet finite element modal, a topology optimization was carr ied out, depended on which tendons were laid on the cabinet. Compared with the p revious consequence, the modal frequency rose and modals at mid and low frequenc y band decrease markedly, and the optimized cabinet avoided the resonance while the hydrogen pump operating.