In order to improve the utilization rate of high-end detector and enhance the applicability of Raman spectrometer to detect different substances at the same time, the integrated design of multiple wavelength excitation Raman spectrometer into a spectrometer will have important application value.A design method of dual-channel Raman spectrometer based on CT structure dual wavelength excitation (532nm and 785nm) is proposed.Based on the working characteristics of the detector, the design method adopted creates conditions for the simultaneous operation of the dual optical path structure, thus maximally increasing the spectrum measurement range. At the same time, the method also realizes the full utilization of the effective photosensitive surface pixels of the detector and the maximum realization of the hyperspectral resolution. The optimized results show that the resolution is 5cm-1 and the spectral range is 80~4200cm-1 for 532nm excitation wavelength.For 785nm excitation wavelength, the resolution is 3cm-1 and the spectral range is 200~2300cm-1.