[Aim]  To determine the benefits of adding synergists to four novel insecticides to control Aphis gossypii; specifically, to clarify if these reduce the amount of insecticide used and improve the effectiveness of control. [Methods]  The leaf-dip method was used to evaluate the effects of synergists on the toxicity of novel insecticides to A. gossypii. Surface tension, contact angle, and retention, were measured to analyze the effects of synergists on the physicochemical properties of each insecticide. Field efficacy was further evaluated using the stem-leaf spray method. [Results]  All six synergists showed varying degrees of synergy with the four insecticides tested. Synergistic ratios ranged from 6.35-274.36 for flupyradifurone, 3.00-26.40 for broflanilide, 2.69-17.57 for triflumezopyrim, and 1.01-11.37 for afidopyropen. Physicochemical analyses revealed reductions in surface tension (1.76%-38.56%) and contact angle (0.16%-15.79%), with synergists differing in their effects on solution retention. Field trials confirmed significant improvements: The combination of Zhongbao Yunwenqing and afidopyropen had the best efficacy and persistence, with a control rate of up to 99.68% after 14 days. Green tangerine peel oil, Zhongbao Yunwenqing, and Jinnuo improved the effectiveness of spraying triflumezopyrim by 29.18%-69.01%. Green tangerine peel oil and Zhongbao Yunwenqing improved the effectiveness of broflanilide by 32.57%-47.69% and 35.20-47.40%, respectively. Green tangerine peel oil, Zhongbao Yunwenqing, and Letou improved the effectiveness of flupyradifurone by 1.62%-12.86%. [Conclusion]  The combination of 50 g/L afidopyropen DC (reduced by 30%) with Zhongbao Yunwenqing was the best in terms of control, followed by 17% flupyradifurone SL (reduced by 30%) and Letou. These results offer a theoretical basis and practical guidance for the environmentally friendly, and rational, use of insecticides to control of A. gossypii.