The fuel cell engine test system provides a stable, safe and convenient test platform for fuel cell engine function and performance testing; it is suitable for applications such as fuel cell engine R&D test, ex-factory test and incoming material inspection. The system includes the water, electricity and gas supply units required for the operation of the fuel cell engine. It also includes a monitoring unit for the operation status of each unit of water, electricity and gas, and monitors the operating state of the fuel cell engine in real time, and the energy is fed back to the grid. At the same time, the system also integrates perfect security protection functions, and adopts double security protection measures combining software and hardware to ensure the security and stability of the testing process.