Hydrogen fuel is a potential energy source for vehicles in the future. The emission of this fuel complies with the stringent policies issued by the International Energy Agency (IEA). Researchers have nominated the hydrogen compression ignition engine in an argon atmosphere as one of the ways to enhance power output and volumetric efficiency in the midst of pre-ignition and knock problems. Since this type of research is still in the initial stage, numerical studies have become the best method for researchers to obtain data on hydrogen fuel combustion in an argon-oxygen atmosphere. The purpose of this study was to validate the simulation results with the experimental data, investigate the combustion characteristics of hydrogen fuel in an argon-oxygen atmosphere, and to study the effects of the initial temperature and injection pressure on the combustion process. In this research, CONVERGE CFD software was used for the simulation process. When the ambient temperature increased, there was a decrease in the pressure but an increase in the heat release rate. On the other hand, when the injection pressure was increased, the in-cylinder pressure and the heat release rate decreased slightly.