The invention discloses a method of evaluating the effective operation energy consumption of a dynamic load electro-dynamic unmanned aerial vehicle (UAV), comprising the following steps: measuring and calibrating the no-load mass M0 of an electro-dynamic UAV; installing a variable-mass load on the electro-dynamic UAV; starting the electro-dynamic UAV, keeping the speed and torque of the motor unchanged, making the mass of the load on the electro-dynamic UAV gradually decrease to Mk, and recording real-time voltage, current and other data of the motor; restating the electro-dynamic UAV, keeping the mass of the load on the electro-dynamic UAV unchanged, gradually changing the speed and torque of the motor, and recording real-time voltage, current and other data of the motor; calculating the load coefficient K, operation efficiency ETAem and power factor of the motor of the electro-dynamic UAV; calculating the electric energy consumption of the UAV in the two operation processes; and analyzing the factors influencing the energy consumption of the motor system of the electro-dynamic UAV. Through the method, the energy consumption of agricultural UAVs can be known, and reference and support are provided for energy saving optimization of UAVs.