The invention relates to erbium-doped transparent glass ceramic containing nanocrystalline barium yttrium fluoride and the preparation method thereof, which relates to the field of luminescent material. The components of glass ceramic are (mole ratio): 40SiO2-25Al2O3-xBaCO3-10YF3-yBaF2-zErF3 (x=5-20, z=0.1-3.0, y=25-x-z). The invention is prepared by melt-spinning technique and adopts SiO2, Al2O3, BaCO3, YF3, BaF2 and ErF3 powder as raw materials, and the raw materials are well mixed, heated to 1300-1600 DEG C and the temperature is preserved for 1-4 hours, and then melting fluid is prepared into vitreous body; the vitreous body is annealed to relieve internal stress, continues to be heated to 650-800 DEG C, the temperature is preserved for 1-10 hours, and the obtained nanocrystalline has extremely high solid solubility of erbium ion. With the infrared excitation, the up-conversion emission intensity of the glass ceramic is greatly improved by adjusting heat treatment temperature.