Metal halides low-dimensional perovskites have highly efficient luminescent properties and shown great potential as scintillators for radiation detection applications. Herein,single crystal of all-inorganic zero-dimensional Cs3Cu2Br5 was grown by the Bridgman technique. The optical absorption, photoluminescence emission and excitation, time-resolved photoluminescence, and X-ray detection performance of Cs3Cu2Br5 were measured. The Cs3Cu2Br5 crystallized into orthorhombic system with a space group of Pnma. Under the excitation of X-ray, Cs3Cu2Br5 crystal has a broad emission peaking at about 467 nm originated from self-trapped exciton emission. The steady state light yield of Cs3Cu2Br5 is about 4 000 ph./MeV and its afterglow performance is comparable to that of BGO crystal.