Abstract: Raman detection is often disturbed by fluorescence background, while Shifted Excitation Raman Difference Spectroscopy(SERDS)is an effective method for fluorescent suppression on Raman spectroscopy. Based on this method, a Raman spectroscopy measurement system was designed using two closely space fixed-wavelength laser diodes stabilized with the Volume Bragg Gratings. The output wavelength of laser diodes was stabilized by manipulating their power and temperature. The light path and circuit of spectral data acquisition were designed with back-thinned area array CCD with high sensitivity. Besides, the three different reconstruction algorithms of the difference spectrum, namely simple integration algorithm, simple integration with data interpolation algorithm and multiple energy constraint iterative deconvolution algorithm could be realized through software of this system. The Raman spectra of sesame oil of some brand in the presence of a highly fluorescent were measured with this system and then the spectra reconstructed with three different algorithms to process the difference spectrum respectively were compared. Experimental results show that the system designed in this paper can effectively reject the effect of fluorescence to the Raman spectroscopy measurement.