Hydrogen as a clean fuel, combustion in theory only generates water, does not produce carbon emissions, is an excellent alternative fuel for internal combustion engine, hydrogen internal combustion engine route can make an important contribution to emission reduction in the future. This paper mainly introduces the new design of special hydrogen engine for HEV based on gasoline engine platform. Different cylinder head, supercharger and injector schemes are designed respectively hydrogen engine tests, verify the thermal efficiency and NOx emissions of hydrogen engine, and study the influence law of different control variables on the thermal efficiency and NOx emissions of hydrogen engine. Then, by optimizing different control variables, the performance differences of different schemes are verified and the best scheme is determined. It provides technical reserve and experience for the development of new hydrogen engine.