In this study，a gold nanocrystal colloid was used as the enhancement factor for surface-enhanced Raman scattering(SERS).Raman spectra were transformed by continuous wavelet transform(CWT)，and Mexican hat wavelet were chosen as the wavelet basis.This procedure could be used to alleviate the influence of baseline variations and random noise，and find peak positions and the best scale wavelet coefficients of signal-Reverse search method was proposed to compare the spectrum of an unknown sample with a spectrum of standard using the information in wavelet space.Reverse match quality(RMQ)could be obtained automatically to determine whether a substance is present.It was used to identify colorants in a variety of food successfully.The colorants could be identified with 99 percent accuracy.It shows a better performance compared with traditional hit quality index(HQI).The study confirmed that the wavelet-based reverse search is feasible and accurate in qualitative analysis.