Abstract: Temperature rise is an important issue during the fast filling of a composite overwrapped pressure vessel (COPV) for hydrogen storage. There exists a thermal-mechanical coupling effect due to the non-uniform temperature distribution and different thermal expansion coefficients. In this study, a fluid-thermal-solid coupling analysis method is proposed for the thermal-mechanical behavior of COPV during fast filling. In this method, a computational fluid dynamics (CFD) model is set up first to obtain the temperature field, which is input into a thermal-mechanical model as boundary condition. By this method, the influences of filling rate, inlet location and geometry of the COPV on the temperature and stress fields are studied. The results of this work will provide a guidance for the design of COPV and the optimization of filling processes.