Abstract: In the integrated vehicle fluids (IVF) system, hydrogen-oxygen internal combustion engines play a crucial role, with a focus on the port fuel injection-hydrogen (PFI-H₂) strategy into the intake manifold. The research aims to study cylinder combustion characteristics, output power, and other parameters under this injection strategy, analyzing hydrogen internal combustion engine performance from multiple perspectives. In order to establish a PFI-H₂ combustion strategy for hydrogen-oxygen internal combustion engines used in IVF systems, a one-dimensional simulation model for PFI-H₂ was constructed using GT-power simulation software. The simulation model was validated using ignition performance data. The results indicate that the one-dimensional combustion performance simulation can provide output power of hydrogen-oxygen internal combustion engines under different operating conditions. The power ranges from 6 to 8 kW, which meets design requirements. The effective thermal efficiency ranges from 29.17% to 30.08%, and the proportion of exhaust energy in this region has little change, concentrated in 46%~48%.