【Objective】This study aims to investigate the residual efficacy and duration of various trunk-injected agents on masson pine (Pinus massoniana). Assess transport distribution, residue dynamics, and control effects on pine wilt disease. Evaluate 5% (mass fraction) emamectin benzoate soluble liquid, 5% abamectin emulsion, and 1% emamectin benzoate-9% imidacloprid soluble liquid agents.【Method】Sampled at different parts of the pine tree in layers. Analyzed residue dynamics in the tree using liquid chromatography-mass spectrometry (LC-MS). Quantitatively analyzed the translocation, distribution, and residue dynamics of the chemical within pine trees. Following trunk injection, inoculate the pines and design a secondary inoculation to simulate continuous nematode infestation; continuously monitor and record disease development to evaluate the chemical's long-term protective efficacy.【Result】Three trunk-injected agents effectively reached various parts of Pinus massoniana, with the main trunk showing the highest residue levels and branches less so. Residues generally lasted about three years, peaking in the first year, then declining. The 5% emamectin benzoate had the best transport and residue, maintaining a 24.609 mg/kg residue level after three years, and remained at a 37.50% control efficacy after a second inoculation. Abamectin showed rapid degradation, with no residue detected in top branches after three years, and only 12.50% efficacy after a second inoculation. The 1% emamectin benzoate-9% imidacloprid had lower nematode control, resulting in the earliest onset. Higher doses effectively increased residue levels, with 60 mL 5% emamectin benzoate reaching 33.900 mg/kg after one year, much higher than 30 mL 5% emamectin benzoate's 2.405 mg/kg. Injection methods had little effect on residue distribution at 1 and 2 a.【Conclusion】Three trunk-injected agents can be transported to all parts of the tree after injection. Compared with the other two, 5% emamectin benzoate has higher transport efficiency and residual amount, making it the preferred agent for long-term prevention and control of pine wilt disease. All three agents can effectively prevent pine wilt disease for a relatively long time after injection. The residual amount and control effect are still significant one or two years after injection, but the control effect decreases significantly three years after injection.