In this study, the silver colloid solution biosynthesized by Lilium casa blanca petals powders was used as the Surface-enhanced Raman Scattering (SERS) active substrate to establish a SERS detection method for amoxicillin content in milk. The effect of the concentration of silver colloid solution, the volume ratio of silver colloid solution and amoxicillin solution, and the addition of sodium chloride on SERS detection were investigated to optimize the detection conditions. The results showed that, under the conditions of the concentration of silver colloid solution of 106.04 μg/mL, with the volume ratio of silver colloid solution and amoxicillin solution of 4:1, and without adding sodium chloride, the SERS signal was the strongest. Under these conditions, the concentrations of amoxicillin solution had a good linear relationship with the SERS intensity at 1 055 cm^-1 in the range of 1～1 000 μg/mL, with a minimum detectable concentration of 1 μg/mL. The recoveries of amoxicillin in the three spiked milks ranged from 84.51% to 93.62% with a relative standard deviation (RSD) of 5.16%. In conclusion, using this simple and convenient method, a certain concentration of amoxicillin in milk could be detected.