Abstract: Due to the unique physical and chemical properties such as high light absorption coefficient, narrow emission spectrum, high photoluminescence quantum yield, and adjustable composition and size, metal halide perovskite nanocrystal have demonstrated extensive application potential in optoelectronic technologies including light-emitting diodes, solar cells, photodetectors, catalysis, lasers, and fluorescence sensing, and have become a research hotspot in the field of materials science. Based on their application in fluorescence sensing, this paper focuses on summarizing the preparation techniques of metal halide perovskites nanocrystal, the fluorescence sensing mechanism, and the research progress in this field. Meanwhile, it discusses the stability issues faced in the application of metal halide perovskites nanocrystal in fluorescence sensing and their corresponding solutions. Finally, the development direction of metal halide perovskite materials with higher optical performance and stability is summarized and prospected. This paper aims to provide a reference for researchers to develop efficient and stable perovskite materials through a comprehensive review and analysis of their applications in fluorescence sensing.