In this paper, indomethacin are characterized by the spectroscopy of UV and Raman and surface enhanced Raman scattering (SERS) on the substrate of L-Cys@Ag. And compared with the conventional Raman spectra (NRS) of solid indomethacin, it was found that L-Cys@Ag had significant Raman enhancement for indomethacin, but the characteristic peak was almost unchanged. The Raman spectra of indomethacin on L-Cysteine/silver were analyzed by the adsorption model of L-Cysteine and silver under acidic and basic conditions. The results showed that L-Cysteine and silver were mainly adsorbed by Ag—S bonds, but neutral and alkaline conditions carboxyl were also adsorbed to the surface of silver. The reson why the overall energy decreases is that the amino groups in the cysteine react with the carboxyl groups in the indomethacin and the π electrons in the benzene ring. After adding bovine serum albumin (BSA), the SERS intensity was significantly decreased at pH 5. At pH 7, and pH 9, the NH stretching vibration and amide II vibration were obviously enhanced, as well as the benzene ring and indole ring of indomethacin. The peak vibration disappeared due to the disappearance of indole mesacin, and the nitrogen and carbonyl groups in indomethacin were adsorbed by amino groups in BSA, and the C—N And —COO’s SERS signal is stable. This provides a reliable method for the identification and analysis of the future improvement of indomethacin and related non-Zhiban anti-inflammatory drugs and new drugs.