The invention relates to a preparation method of anisotropic bulk metallic glass. The method comprises the following steps that 1, an alloy rod with the specific size and components is prefabricated and put into a specially-made tubular crucible; 2, the tubular crucible containing the prefabricated alloy rod is integrally heated with a heating device to enable the prefabricated alloy rod to be completely molten; 3, the tubular crucible is driven by a drawing rod to be submerged into a cooling medium downwards in the axial direction at a certain constant speed, and then preparation of the anisotropic full-amorphous bulk metallic glass is completed. According to the preparation method, by controlling and unidirectionally cooling heat flow generated in the preparation and solidification process of the bulk metallic glass, rearrangement of short-distance ordered cluster structures in the bulk metallic glass is achieved, and preparation of the anisotropic full-amorphous bulk metallic glass with the macro-mechanical properties is completed.