The study conducted a two-year field experiment to explore the effects of pesticide application via under-mulch drip irrigation on the control efficacy of major pests and comprehensive benefits in the field propagation of disease-free sugarcane original seedlings. With no pesticide application as the control (CK), four treatments were simultaneously set up, two drip irrigation pesticide application treatments (T₁ and T₂: applying 40% chlorantraniliprole·thiamethoxam WG via drip irrigation 3 times and 2 times, respectively), one unmanned aerial vehicle (UAV) spraying treatment (T₃: spraying 40% chlorantraniliprole·thiamethoxam WG 2 times), and one conventional root application treatment (T₄: applying 4% imidacloprid·bisultap GR 2 times). A comprehensive comparative analysis was performed on indicators such as the control efficacy against sugarcane borers, thrips, and aphids, as well as the propagation efficiency and economic benefits of disease-free sugarcane original seedlings, aiming to provide a theoretical basis for scientifically guiding sugarcane elite seed propagation bases to utilize existing under-mulch drip irrigation systems for efficient and economical control of major pests. In the early stage of seedling propagation, the two drip irrigation treatments (T₁ and T₂) exhibited the best control efficacy against the rate of borer-induced dead heart seedlings, reaching over 76.00%, with the dead heart seedling rate controlled below 1.20%, which was significantly lower than that of other pesticide treatments. In the middle and late stages of propagation, UAV spraying T₃ showed the highest control efficacy against the rate of borer-damaged plants, reaching 72.00%, followed by the two drip irrigation treatments T₁ and T₂ with control efficacy ranging from 61.00% to 66.00%. Specifically, except that the rate of borer-damaged plants of T₃ was significantly lower than that of T₂ in the 2023 experiment, there was no significant difference in the rate of borer-damaged plants between T₃ and T₁, T₂. Conventional root application T₄ had the lowest control efficacy, and the rate of borer-damaged plants was significantly lower than that of other pesticide treatments. In terms of the rates of borer-damaged internodes and borer-damaged buds, drip irrigation treatment T₁ (applied 3 times) showed the highest control efficacy, both reaching over 82.00%, with the rates of borer-damaged internodes and buds controlled below 0.73% and 0.28%, respectively, which were significantly lower than those of other pesticide treatments. For the two foliar pests (thrips and aphids), UAV spraying T₃ showed better control efficacy than other treatments, reaching over 70.00%, but there was no significant difference compared with the two drip irrigation treatments. In terms of seedling propagation efficiency, drip irrigation treatments T₁ and T₂ had the highest number of effective buds, reaching 138.71×10⁴, 136.53×10⁴ buds per hectare, respectively, which was more than 6.12% higher than that of conventional root application T₄, but there was no significant difference compared with UAV spraying T₃. In terms of comprehensive propagation benefits, compared with CK, drip irrigation treatments T₁ and T₂ had the highest increase in net income, reaching 31 300, 30 400 yuan/hm², respectively, with an input-output ratio of above 1∶30, which was much higher than the input-output ratio of approximately 1∶21 for UAV spraying T₃ and conventional root application T₄. Comprehensively, applying 40% chlorantraniliprole·thiamethoxam WG via drip irrigation 3 times can sustainably and efficiently control borers, thrips and aphids, balances propagation efficiency and benefits, and has the lowest rate of borer-damaged internodes in seed canes. Thus, it can be used as the optimal scheme for controlling above-ground pests in the field propagation of disease-free sugarcane original seedlings.