The invention discloses a hydrogen-fuel unmanned aerial vehicle and an estimation method for endurance time of an unmanned aerial vehicle. A gas tank pressure intensity and a gas tank capacity of an unmanned aerial vehicle are detected and thus a residual energy of the gas tank is calculated; hydrogen-fuel battery output current values and voltage values at all times during flight of the unmanned aerial vehicle are collected and then an output power is obtained; and according to the residual energy and an average output power, endurance time of the unmanned aerial vehicle in a stable state is obtained. For a complicated flight situation, the changing value of the gas tank pressure within certain time and the average output power within the time are detected to obtain the energy consumption within the time; on the basis of proportion calculation with the residual energy, the flight time of the vehicle with the residual energy can be obtained. On the basis of the gas tank pressure value and other series of practical detection values, real-time estimation is carried out on the endurance time of the unmanned aerial vehicle to obtain the endurance time of the unmanned aerial vehicle, so that reliability, practicability, and security of the unmanned aerial vehicle are improved substantially.