The invention relates to a yttrium-doped barium fluoride crystal and a preparation method and an application thereof. A chemical composition of the yttrium-doped barium fluoride crystal is Ba(1-x)YxF2+x, wherein x is greater than or equal to 0.01 and less than and equal to 0.50. The scintillation property of the BaF2 crystal is improved, yttrium doping can greatly inhibit slow luminous component of the BaF2 crystal, and the fast/slow scintillation component ratio is excellent, the doped crystal and a photo-detector are subjected to coupling to produce a scintillation probe. The yttrium-doped barium fluoride crystal is suitable for fields of high-time distinguish radiation such as high-energy physics, nuclear physics, super-speed imaging and nuclear medicine imaging.