The ?5 mm Cs₃CdBr₅ single crystals were grown using the Bridgman method， and Cs₃CdBr₅-CsBr composite scintillator were formed by CsBr encapsulating Cs₃CdBr₅ in the cone of the ingot. We conducted phase analysis on the crystal which explained the formation of composite scintillators， and investigated the photoluminescence and X-ray excited luminescence properties. The Cs₃CdBr₅ crystal belongs to the tetragonal crystal system with a space group of I4/mcm. It is of a 0-dimensional perovskite structure. The emission peaks of Cs₃CdBr₅ single crystal excited by fluorescence and X-ray are at 374 and 365 nm， respectively. The decay time of photoluminescence is 0.4 and 16.6 ns， while the decay time of X-ray excited luminescence is 15.9 ns， which is the intrinsic luminescence of Cs₃CdBr₅ with self-absorption. Under the same excitation， Cs₃CdBr₅-CsBr composite scintillators exhibit relatively stronger luminescence peaking at 365 nm， with photoluminescence decay time of 0.97 and 14.79 ns， X-ray excited luminescence decay time of 17 ns. There is luminescence of CsBr peaking at 438 nm under X-ray excitation， which contributes to sub-millisecond slow fraction. The Cs₃CdBr₅-CsBr composite scintillator exhibits an energy resolution of 56.9% and a light yield of 257 photons/MeV when excited by ²⁴¹Am source. The good environmental stability and special 0-dimensional perovskite structure make doped crystals based on Cs₃CdBr₅ promising scintillation crystals with practical application value.