The invention relates to a holmium-doped gadolinium-yttrium-barium fluoride crystal and a growth method thereof, belonging to the technical field of optoelectronic materials. The conventional Ho:BaY2F8 crystal has low doping concentration, small size and bad crystal morphology. The holmium-doped gadolinium-yttrium-barium fluoride crystal belongs to a monoclinic system, rare earth element holmium is used as active ions, a crystal matrix is gadolinium-yttrium-barium fluoride, and the molecular formula of the holmium-doped gadolinium-yttrium-barium fluoride crystal is Ho:BaYGdF8. The growth method for the holmium-doped gadolinium-yttrium-barium fluoride crystal comprises the following three steps of: preparing a growth material, performing crystal growth and annealing. In the step of preparing the growth material, elements such as F, Gd, Y and Ba served as raw materials are provided in a molar ratio of BaF2: GdF3: YF3 equal to 1:1:1, HoF3 is determined as x mol, GdF3 is determined as (1-x) mol, BaF2 is determined as 1 mol, and the value scope of the x is more than or equal to 0.005 mol and less than or equal to 1 mol; and in the step of performing the crystal growth, process parameters for the crystal growth are determined as follows: the withdrawal pulling rate is between 0.3 and 0.8mm/h, the rotation speed is between 3 and 10rmp, and the growth temperature is between 880 and 903 DEG C.