Abstract:In this paper, the capillary substrate is prepared by Adsorption of silver nanoparticles on the inner wall. By using surfaceenhanced Raman spectroscopy (SERS) to detect pesticide dimethoate in Rapeseed oil, under neutral conditions pesticide dimethoate concentration was found to be 200 mg/kg, and under acid conditions pesticide dimethoate concentration was found to be 0.1 mg/kg. It is close to the national safety standard of maximum pesticide residue(0.05 mg/kg) in vegetable oils. The experimental results showed that the surfaceenhanced Raman spectroscopy technology can be used as an effective method for detecting the residues of Dimethoate pesticides in Rapeseed oil.