A three-axis vibration platform is first constructed and utilized in the investigation of the effects of mechanical vibration on the cold start performance of a proton exchange membrane (PEM) fuel cell. In addition, an intermittent pattern of purging is adopted to improve the purging efficiency. The applied vibrations are found to promote water dispersion, but ultimately do not enhance water removal. Under subzero conditions (−13 °C), the vibration of the fuel cell improves cold start performance via delayed freezing, especially when vibrating at the fuel cell natural frequency (10 Hz). With an increase in vibration amplitude, the freezing rate is found to be slow and eventually plateau. Finally, the vibration in the vertical axis is found to play a positive role in improving cold start performance; the effects of other orientations depend on the startup temperature. The result of cold start under vibration might indirectly prove the existence of super-cooled water.