Luminescent lanthanide compounds stand out for their distinctive characteristics including narrow emission bands, substantial Stokes shifts, high quantum yields, and unique luminescent colors. However, Ln3+ is highly susceptible to vibrational quenching from X-H (X = O/N) high-energy oscillators in the embedded organic antenna, resulting in significant nonradiative energy dissipation of the 5D excited states of Ln3+. Herein, we introduce a strategy based on supramolecular interactions to modulate the nonradiative transitions in a new ZnII-TbIII heterometallic compound, [ZnTb(HL)2(NO3)Cl2]·2CH3CN·H2O (ZnTb), based on a phenyl-substituted pyrazolinone-modified salicylamide-imide ligand (H2L). The regulation mechanisms are explored in detail both experimentally and theoretically. With the N,N'-dimethylformamide (DMF)-boosted Tb3+ luminescence, ZnTb⊃DMF (1 mg of ZnTb + 2 mL of DMF) realizes a rapid (3s) and sensitive detection of water in DMF with a detection limit of 0.021%. Further, ZnTb⊃DMF can detect trace amounts of water in ethanol and ethanol gasoline with a low detection limit of 0.023% and 0.048%. In addition, portable paper strips of ZnTb⊃DMF are prepared to improve its practicability, which can afford real-time and faster (1 s) in situ visual sensing of trace amounts of water in common organic solvents and ethanol gasoline with sensitivity comparable to the titration results. This study provides a new idea for the lanthanide luminescence modulation and application in the field of fluorescence sensing.