Hydrogen-powered aircraft is an important development direction for the aviation industry to achieve green energy transformation and is expected to be put into use by 2027. Many countries around the world are conducting hydrogen fuel cell power modification tests for regional aircraft. This paper proposed a hydrogen fuel cell power modification design based on the existing turboprop regional aircraft platform, then analyzed the performance indicators such as payload and range after the modification. According to the research in this paper, the passenger capacity and maximum range of the modified aircraft have been reduced by 26.7, and 43.3% respectively. Although the current performance level of hydrogen-powered aircraft lags behind that of conventionally powered aircraft, it still has sufficient development potential. The pioneering application of hydrogen fuel cells on regional aircraft will be an important step in the development of sustainable aviation.