Taking a fuel cell vehicle as the research object, considering the vehicle layout environment and thermal management requirements comprehensively, a complete thermal management system of hydrogen fuel cell vehicle is designed. The key components are selected and designed to match the performance. At the same time, AMESim software is used to build a one-dimensional simulation model of thermal management system and verify its credibility. Using the coolant input flow rate, components’ inlet and outlet temperatures and temperature difference as the evaluation indicators, the simulation analysis of the thermal management system of hydrogen fuel cell vehicle under different working conditions is carried out. The results show that the system works well and meets the design requirements except that when the outlet water temperature of the stack and intercooler reaches the limit value under the peak condition, it is not suitable to work for a long time. The proposed thermal management system can provide some design ideas for the future research and development of the thermal management system of fuel cell vehicles.