Plastic fracturing balls are generally produced using PLA, which is a degradable material, but the shrinkage rate of PLA materials is extremely large. In theory, the thickness of plastic products produced by PLA should not exceed 4mm, but the smallest diameter of plastic fracturing balls is also a sphere with a diameter of 10mm or more. The mold of the fracturing ball is required to have the characteristics of fast heat dissipation. When the injection is completed, the heat of the fracturing ball is quickly lost through the mold cooling water, so that after the surface of the fracturing ball is solidified, it is not easy to shrink.