In recent years, Cs₂ZnCl₄ crystal has become an ideal substrate for various functional doped ions due to its large bandgap, showing potential in photodetectors and scintillators. In practical application, the intrinsic defect luminescence of bulk crystals has an important effect on the photoelectrical properties. In this work, Ø12 mm × 90 mm Cs₂ZnCl₄ single crystal was grown by the vertical Bridgman method. The theoretical bandgap, state density distribution, and refractive index curve of the crystal were obtained by first-principles calculation of the structure data. The luminescence properties of the crystal were characterized, including photoluminescence spectrum and radioluminescence spectrum. The temperature-dependent photoluminescence spectrum of the crystal was studied, and the luminescence process of the defects in the crystal was analyzed by the experimental results.