Extended PE double-walled pipe is a technology that hollow walled pipe widens hollow wall to the side extruded as a square and extrudes the form added with a stiffener of I-BEAM shape from the time of initial pressing out when producing existing double walled pipe. It can improve production speed 1.6 times faster. Plastic pipes used in study were PE pipe, especially HDPE pipe that is safe from reproduction of seaweed and bacteriomycota and can be used semi permanently as a few corrosion by corrosive substance existing in soil is made. The purpose of this study is to decrease production time and increase outputs by extending width of extruding side 1.5 times wider when producing PE double walled pipe through making existing double walled pipe into extended PE double wall. Also, it is aimed to develop an extended PE double-wall pipe that can eliminate causes of defect occurred by middle pipe wound around with drawing machine 90°when producing existing goods.