This paper focuses on the powertrain modeling of hydrogen electric buses based on a numerical analysis. The powertrain, which consists of an electric motor, inverter, battery, and hydrogen fuel cell, is one of the key elements of a hydrogen electric bus. Accordingly, the efficient design and operation of the powertrain have a significant impact on the performance and cost-effectiveness of hydrogen electric buses. Therefore, accurately modeling and analyzing the powertrain of hydrogen electric buses is essential in performance evaluation and optimization under actual operating conditions. The objective of this study is to understand and analyze the operation and performance of the hydrogen electric bus powertrain through modeling and simulation. This will enable the derivation of efficient operating strategies and optimal powertrain configurations, leading to the improvement and widespread adoption of hydrogen electric buses.