Monitoring hydrogen sulfide (Hsub.2S) in living organisms is very important because Hsub.2S acts as a regulator in many physiological and pathological processes. Upregulation of endogenous Hsub.2S concentration has been shown to be closely related to the occurrence and development of tumors, atherosclerosis, neurodegenerative diseases and diabetes. Herin, a novel fluorescent probe HND with aggregation-induced emission was designed. Impressively, HND exhibited a high selectivity, fast response (1 min) and low detection limit (0.61 μM) for Hsub.2S in PBS buffer (10 mM, pH = 7.42). Moreover, the reaction mechanism between HND and Hsub.2S was conducted by Job’s plot, HR-MS, and DFT. In particular, HND was successfully employed to detect Hsub.2S in HeLa cells.