Fluorescence interference is a major challenge in Raman spectroscopy, as strong fluorescence will seriously affect the detection of Raman spectroscopy signals. This paper introduces several differential Raman spectrum restoration methods (integration method, curve fitting method, deconvolution method, etc.) of shifted excitation Raman difference spectroscopy for defluorescence technology, and discusses its principle, implementation, and performance characteristics. In addition, the application of differential Raman spectroscopy in food, medicine, agriculture and other fields is analyzed in detail, which shows that shifted excitation Raman difference spectroscopy has broad application prospects.