In order to solve the problem of load configuration for optimal dynamic energy consumption of agricultural multi-rotor UAVs, a method of optimizing the dynamic energy consumption for agricultural UAVs by load configuration according to their power systems and number of rotors was proposed. Firstly, on the basis of established dynamic energy consumption model for agricultural UAVs, the dynamic energy consumption corresponding to the load of seven different rotor numbers (four-rotor to ten-rotor) under three kinds of motor power system configuration was calculated respectively. Then the load-dynamic energy consumption curves corresponding to different rotor numbers were plotted. And the data processing software was used to ‘intersect’ the curves to get the intersection points of the load-dynamic energy consumption curves under different rotor numbers. It was found that for agricultural UAVs with different rotor numbers for the same power system configuration, the intersection of the load-dynamic energy consumption curves for the two adjacent axis rotor number configurations was the optimal dynamic energy consumption load intersection. The load values corresponding to the intersection points of the optimal dynamic energy consumption load can form the optimal dynamic energy consumption load interval from small to large, which was the optimal load configuration interval corresponding to different rotor numbers. The dynamic energy consumption of the agricultural UAVs can be optimized by using the above method to configure the load according to the number of rotor numbers. Finally, totally 80 flight verification tests of different loads were carried out by using the designed agricultural UAV with four, six and eight rotor structures. The test data showed that there was optimal dynamic energy consumption load configuration interval under different rotor configurations of four, six and eight. Among them, the average error between the test value and the theoretical value of the four-rotor UAV dynamic energy consumption was 3.22%. The average error of the six-rotor UAV was 2.87%. The average error of the eight-rotor drone was 2.85%. Furthermore, through the error analysis of the flight measured dynamic energy consumption value and the theoretical calculated energy consumption value, the optimal dynamic energy consumption load effective zone and failure zone was acquired. And then a more accurate optimal dynamic energy consumption load configuration interval was acquired. The research result can provide a reference for optimizing the load configuration of agricultural multi-rotor UAVs, which had certain theoretical significance and engineering practice value.