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[Display omitted] • Adsorption behavior of pyridaben on silver surface was firstly given. • Adsorption behavior of pyridaben was studied by both calculation and experiment. • Result of pyridaben adsorption behavior study was used for its SERS detection. • SERS method to detect pyridaben residues in apple was firstly presented. • The LOD of pyridaben residues in apple can be as low as 0.08 mg/kg. It is widely accepted that the sensitivity of SERS is mainly manipulated by the interactions between analyte molecules and metallic nanostructures. Herein, the adsorption behavior of pyridaben on silver surface was investigated systematically by DFT simulation and SERS verification for the first time. The adsorption site and ideal adsorption model of pyridaben were predicted by the simulate parameters of pyridaben, pyridaben-Ag 3 , pyridaben-Ag 4 , and pyridaben-Ag 6 obtained by DFT calculation, and the enhancement mechanism of Raman characteristic peaks was analyzed by comparing the Raman spectra of pyridaben and pyridaben-Ag 4 complex. The results showed that pyridaben was mainly vertically adsorbed on silver surface through the S atom of pyridaben. The adsorption model of pyridaben-Ag 4 complex was more stable, and SERS enhancement effect of pyridaben originated from the charge transfer effect between pyridaben molecule and Ag 4 cluster. Further, the potential practical application of the adsorption behavior study was evaluated by residue detection of pyridaben in apple. The method showed low LOD of 0.08 mg/kg, the linear range was 0.10–10.00 mg/kg, recovery ranged from 79.71 % to 113.98 %, and RSD was less than 16.16 %. These results promoted the application of SERS technology in pesticides residue detection. [ABSTRACT FROM AUTHOR]