The Raman peak of Ciprofloxacin (CIP) was calculated by the density functional theory (DFT) B3LYP/6-31G(d, p) basis set, compared with the experimental Raman peak. The degree of fit is high. And its Raman Peak has been fully vested. The surface enhanced Raman spectroscopy (SERS) and conventional Raman experiments of ciprofloxacin showed that the gold nanoparticles were used as the substrate to enhance the Raman peak of ciprofloxacin. The effect of binding time on the mixture of aminophylline and ciprofloxacin was explored. The results showed that the interaction between the two increased with time, and the partial Raman peak of ciprofloxacin disappeared. The addition of aminophylline affected the molecular structure of ciprofloxacin, which caused the haloxixine Raman signal to weaken and many Raman peaks to change, mainly pyrazine ring at 1 184 and 1 252 cm-1. The vibration frequency of C—F at Raman, CC at 1 627 cm-1 and O—C—O at 1 458 cm-1 changed; the increase of aminophylline content had a more serious effect on the structure of ciprofloxacin, of which the Raman peak at 800~1 200 cm-1 disappeared. When the amount of aminophylline exceeded 22.5 mg·L-1, almost no other peak appeared except for the weak signal at 1 384 cm-1. As a commonly used analytical tool, surface-enhanced Raman spectroscopy has the advantages of short analysis time and high sensitivity. The experiment used SERS technology to investigate the interaction between aminophylline and ciprofloxacin, and provided a reference for its pharmacological research.