Hydrogen sulfide (H2S) is the third kind of endogenous "gas messenger molecule" discovered by people at present. It is of great significance to human health to detect it in time. With the development of fluorescence probe technology, the small molecular fluorescence probes have attracted the attention of many scholars. Coumarin is popular because of its simple structure, high fluorescence quantum yield and easy to function. This paper reviews the representative research results of coumarin H2S probes reported in recent three years according to the mechanism of probe identification, and prospects them, which will provide some useful reference for the future design and development of more practical H2S fluorescent probes.