Improving the photoluminescence (PL) efficiency of organic luminescent molecules is still a great challenge. Herein, a novel zero-dimensional Sn(IV)-based halide (C9H8N)2SnCl6 is prepared by assembling inactive quinoline cations and stable [SnCl6]2- polyhedra. Experimental characterizations and theoretical calculations show that the blue emission of (C9H8N)2SnCl6 centered at 433 nm is derived from the organic cations. Surprisingly, the PL efficiency of the as-prepared halide is nearly 50 times higher than that of the organic precursor and exhibits ultrahigh stability. Structural analysis shows that the introduction of inorganic clusters regulates the stacking mode of organic components and forms hydrogen bonds. This strong intermolecular interaction enhances the structural rigidity of (C9H8N)2SnCl6, inhibits concentration quenching and vibrational dissipation, and thus significantly improves the PL efficiency and stability of the organic cations. This work provides an important way to improve the PL performance and stability of organic species by constructing efficient intermolecular interactions.