The present invention provides a rare-earth halide scintillating material and application thereof. The rare-earth halide scintillating material has a chemical formula of REaCebX3, wherein RE is a rare-earth element La, Gd, Lu or Y, X is one or two of halogens Cl, Br and I, 0≤a≤1.1, 0.01≤b≤1.1, and 1.0001≤a+b≤1.2. By taking a +2 valent rare-earth halide having the same composition as a dopant to replace a heterogeneous alkaline earth metal halide in the prior art for doping, the rare-earth halide scintillating material is relatively short of a halogen ion. The apparent valence state of a rare-earth ion is between +2 and +3. The rare-earth halide scintillating material belongs to non-stoichiometric compounds, but still retains a crystal structure of an original stoichiometric compound, and has more excellent energy resolution and energy response linearity than the stoichiometric compound.