Spontaneous Raman spectroscopy exhibits a broad spectrum and high resolution but weak signals; thus, the influence of stray light cannot be ignored. In this study, the mechanism of stray light generation in a self-designed single-cell Raman spectrometer system under gyration rotation is investigated. Moreover, the stray light suppression method is established, particularly the design method for eliminating a stray light optical trap in a multi-structure. The effectiveness of stray light suppression is verified using TracePro software simulation. The analysis results show that after stray light suppression the stray radiation ratios at different wavelengths decrease by 12%?47%, and the overall stray light level of the cell Raman spectrometer is lower than 10^-6. The spectrometer, after the stray light suppression, is valuable for detecting weak light signals.