Raman spectroscopy is used to detect material structure, which is currently one of the fastest growing frontiers in the field of spectroscopy. The detection speed of Raman spectroscopy is very fast and does not require sample preparation, so non-destructive detection can be achieved. The realization of portable Raman spectrometer enables Raman spectroscopy to be used for on-site detection. The portable Raman spectrometer is easy to operate. Moreover, the price is relatively cheap, and the application demand in various industries has become greater. We design a portable Raman spectrometer optical system based on on-site rapid detection. It provides a important foundation for the development and production of portable Raman spectrometers. © 2020 SPIE.