In order to explore the application prospect of veterinary drug fluralaner in the control of agricultural pests, fluralaner was synthesized via seven steps with 4-bromo-2-methylbenzoic acid as starting material and its insecticidal activity was tested. The total yield was 31.11%(the 4-bromo-2-methylbenzoic acid was used for calculation) and the purity of the final product was 98%. The structure of fluralaner was confirmed by 1HNMR 13CNMR and ESI-MS. Meanwhile, lab test results indicated that fluralaner had significant contact activity against Plutella xylostella and Mythimna seperata, and the insecticidal activity reached 100% at a concentration of 1.25 mg/L, fluralaner's insecticidal activity was significantly better than tetrachlorantraniliprole. and fluralaner could be used as lead compounds for further research.