In this paper, using magnetron sputtering technology, the 3D SERS substrates (Ag/OFW substrates) were prepared by depositing silver films on the wings of Odontotermes Formosanus(commonly known as flying ants). By optimizing the preparation conditions, it was found that the substrate possessed the best enhancement effect when the deposition time was 7. 5 minutes. FDTD simulation was used to analyze Ag/OFW substrates enhancement effect with different deposition times. The results demonstrated that the substrate with the sputtering time of 7. 5 min showed stronger electric field distribution; that is to say, the substrate with the sputtering time of 7. 5min possessed the best enhancement effect. It was consistent with the results of using rhodamine 6G (R6G) as a probe molecule to conduct an SERS study on the Ag/OFW substrates with different deposition times. The high-performance substrate exhibited a low detection limit (LOD) of 10-9 mol·L-1 for R6G, indicating an excellent enhancement effect. When the Ag/OFW substrate was employed to solve critical pesticide residue problems for the detection of thiram, the detection concentration of thiram could reach 5. 0×10-8 mol·L-1, which exceeded the detection standard of thiram solution residue (4. 16×10-7 mol·L-1) established by China in 2021. Moreover, the detection method was expected to be used for the rapid detection of the residues of harmful substances.