In recent years, electric vertical takeoff and landing (eVTOL) aircraft has developed rapidly in urban air transportation. eVTOL is taken as the most promising and effective transportation vehicle in market. Safety analysis is the most important condition for reducing catastrophic accidents and ensuring high reliability and high safety during the manned operation of eVTOL. Using functional hazard assessment (FHA) analysis can determine potential failure conditions, expected failure conditions and other hazardous failure conditions in eVTOL, so that potential catastrophic and hazardous failure conditions can be fully identified, and then targeted controlling can finally reduce the occurrence of catastrophic accidents in an all-round way to ensure the safety of eVTOL. Based on the FHA analysis, this paper analyzes the safety of the eVTOL level, and obtains the safety-critical functions through the catastrophic failure conditions, providing a basis for its function design.