Raman spectrometer is an optical instrument widely used in industrial research and laboratory environments for fingerprint identification and analysis of substances. With the changing requirements for measurement environments in practical use, more and more miniaturized Raman spectrometers are being designed, and developing more portable Raman spectrometers has become the goal of researchers. A miniaturized Raman spectrometer can better meet the portable requirements of the instrument, enabling the application of Raman spectroscopy detection technology in a wider range of fields. This article introduces the development paradigm and several types of miniaturized Raman spectrometers, summarizes the key technical issues involved in the research of miniaturized instruments, and introduces their applications, especially in the detection of drugs, toxins, and environmental pollutants on site. Finally, this article looks forward to the research directions and possible application trends of miniaturized Raman spectrometers in the future, providing reference for the further development of miniaturized Raman spectrometers.