This extruder is specially designed and the barrel and screws structure are properly adjusted for the purpose of widening the extruding and inflating function.The modified starch serial products made from this extruder can be used in many fields like pharmacy,spinning, food, paper making, building material, casting, oil drilling and so on. The extruders will definitely play a more important role in modified starch (pregelatinization starch)manufacture field with the research development. This extruder is made up of feeding system, extrusion system, cutting system, heating system, conveying system and cooling system.