To solve the problems of unstable temperature of thermal management system and large coolant temperature difference between inlet and outlet when the power of proton-exchange-membrane fuel cell (PEMFC) changes, using LMS AMESim simulation software, a thermal management system model of PEMFC engine was proposed based on a 30 kW PEMFC engine, considering factors including the power change of the whole vehicle and the driver’s demand. Firstly, the fuel-cell engine calibration condition was used to analyze the coolant temperature and pressure of each component of the thermal management system. Secondly, the New European Driving Cycle (NEDC) was used to simulate the PEMFC thermal management. The results show that the established thermal management system can keep the temperature stable under NEDC working condition, and the maximum temperature difference between inlet and outlet coolant is about 5.6 ℃. This simulation analysis can provide guidance for the thermal management test research of PEMFC engine.