The invention discloses a bullet core preparation method. The bullet core preparation method comprises the following steps that a tungsten alloy and / or elemental tungsten is made into a bullet, a block, a bar, a wire or powder, and a framework material is obtained; the framework material is put into a mold cavity, and the surface of the framework material is covered with alloy powder filler; the mass ratio of the framework material to the alloy powder filler is not less than 3: 1, and the alloy powder filler comprises an amorphous filler and / or a high-entropy alloy filler; and the mold cavity is heated to 600-1,400 DEG C, heating is stopped after the alloy powder filler in the mold cavity is completely melted, cooling is conducted, the alloy powder filler is solidified to completely embed the framework material, and the composite bullet core is obtained. According to the bullet core preparation method, the framework material and the alloy powder filler in a reasonable proportion are compounded, after the alloy powder filler is quickly molten through heating, rapid cooling is conducted, an amorphous tissue structure is formed on the surface of the framework material, and the bullet core higher in breaking strength and hardness can be prepared easily.