Abstract: In this work, the effect of plant protection unmanned aerial vehicle (UAV) spray parameters on the control of Aphis gossypii and the synergistic effects of spray adjuvants on two insecticides were evaluated. The effects of flight height, flight velocity and type of nozzles on the control of A. gossypii was analyzed by field experiments. In addition, the synergistic effects of 5 spray adjuvants (ND-600, ND-800, G2801, BEIDATONG and N380) for two insecticides(22% solfoxaflor SC and 21% thiamethoxam SC) were determined by field trials. The results indicated that spray parameters could significantly affect the control of A. gossypii. 2 m was the best flight height. The optimum parameters combinations were as follows: flight height of 2 m, flight velocity of 3 m/s and nozzle type of IDK120-01. The results also showed that, after the addition of adjuvants, the field control effects of 22% solfoxaflor SC and 21% thiamethoxam SC were improved in different degrees. Except ND-600, 7 days after the application, other adjuvants, including ND-800, G-2801, N380, Beidatong, have synergistic effects on 22% solfoxaflor SC and ND-800. 21% thiamethoxam SC had a good control efficiency for A. gossypii. Control efficiencies were all more than 90% after the usage of adjuvants, ND-600, ND-800, BEIDATONG, G2801 and N380 could all significantly increase the control efficiency of 21% thiamethoxam SC.