In order to facilitate the quantitative analysis of hydrogen-consumption impact factors and hydrogen-consumption potential for fuel cell vehicle, the average integrated transmission efficiency was first defined and a theoretical model of hydrogen-consumption calculation and analysis was proposed, on the basis of the internal energy flow relationship of the fuel cell vehicle during driving. By analyzing the various impact factors of hydrogen-consumption, the theoretical hydrogen-consumption-increment model was further obtained. Finally, based on the fuel cell vehicle model provided by the advisor, the effects of rolling resistance coefficient, mechanical efficiency of the drive train, motor efficiency and fuel cell efficiency on the economics of the vehicle were quantified through theoretical and simulation analysis. In addition, based on the possible-limit state that each influencing factor may reach in the future, the hydrogen consumption potential obtained from the simulation is 0.6 kg/100 km. The quantitative analysis of different factors and the determination of hydrogen consumption potential not only provide critical reference for future research of the fuel cell vehicle powertrain, but also point out the optimization direction for component selection and parameter calibration during the development of actual vehicle.