The extruder, cylinder and screw rods of the machine unit are all made from high-quality alloy steel through nitriding and precision machining, so as to ensure optimal hardness and corrosion resistance, and the output is high and the plasticizing is good by adopting screw rods which are specially designed. The high-speed film blowing machine unit is suitable for blowing various plastic films such as LDPE, HDPE and LLDPE. The plastic film can be widely used for civil and industrial packaging such as food, apparel, trash bags and vest bags.