Three neutral cyclometalated platinum(Ⅱ) complexes were synthesized by liquid-phase coordination complexation. All complexes show aggregation-induced phosphorescence emission (AIPE) properties in THF/H2O. These complexes can be used to detect picric acid in the aqueous phase with a minimum detection limit of 0.10 μmol/L. In the presence of the compounds similar in structure to picric acid or common ionic compounds, the three complexes exhibit high selectivity for detecting picric acid. Moreover, all three complexes can successfully detect picric acid in various natural environments, including seawater, river water, rainwater, and tap water. The mechanism for the detection of picric acid by platinum(Ⅱ) complexes was confirmed to be photo-induced electron transfer through density functional theory calculations and other analytic methods.