Hydrogen is a promising energy carrier because it is characterized by a fast combustion velocity, a wide range of sources, and clean combustion products. A hydrogen internal combustion engine (H2ICE) with a turbocharger has been used to solve the contradiction of power density and control NOx. However, the selection of a H2ICE compressor with a turbocharger is very different from traditional engines because of gas fuel. Hydrogen as a gas fuel has the same volume as its cylinder and thus increases pressure and reduces the mass flow rate of air in cylinder for a port fuel injection-H2ICE (PFI-H2ICE). In this study, a general method involving a H2ICE with a turbocharger is proposed by considering the effect of hydrogen on cylinders. Using this method, we can calculate the turbocharged pressure ratio and mass flow rate of air based on the target power and general parameters. This method also provides a series of intake temperatures of air before calculation to improve accuracy. The calculated compressor outlet temperatures are compared with the theoretical temperatures to obtain accurate data. A fit compressor is selected for a 2.3 L H2ICE and the engine is tested at different engine speed and throttle openings to validate the correctness of this method. The error is below 5% when the experimental turbocharging pressure ratio and mass flow rate of air are compared with the calculated results, and this error is acceptable. Therefore, this method can be used as a basis for the designing and selection of H2ICE compressors.