Hydrogen sulfide (H2S) is emerging as an important biological messenger, and a number of H2S fluorescent probes have been developed. However, lanthanide-based luminescent H2S probes are rarely reported. Here, a terbium complex-based luminescent H2S probe based on the reduction reaction of azide with H2S to amine is present. In the presence of H2S, the probe shows fluorescence ‘turn-on’ response with 12-fold enhancement of Tb3+ emission intensity by modulating excited state energy of the antenna based on intramolecular charge transfer (ICT), and it exhibits high selectivity for H2S over competitive anions and small-molecule biothiols. Moreover, the long luminescence lifetime of the probe facilitates the implementation of time-delayed experiment, whereby the fluorescence with short lifetime can be readily gated out. The time-gated studies demonstrate that time-gated luminescence detection of the probe toward H2S is more precise, not influenced by the background noises caused by fluorescent with short lifetime.