The invention provides an extracting knurling device for a film blowing machine. The extracting knurling device is used for solving the problem that extracting type plastic film bags manufactured by the traditional film blowing machine are difficult in extraction due to the smooth surface. The extracting knurling device comprises a plastic film bag extracting device which comprises two extracting clamping rollers, wherein two ends of the two extracting clamping rollers are respectively fixed on fixing plates on two sides; and the two extracting clamping rollers are parallel to each other in a same horizontal plane. The extracting knurling device is characterized in that a knurling device is mounted on the longitudinal horizontal side of the plastic film bag extracting device; the knurling device comprises a knurling steel roller and a knurling rubber roller; the knurling steel roller and the knurling rubber roller are sequentially mounted on the fixing plates on two sides in parallel in front of the longitudinal horizontal parts of the two extracting clamping rollers; the knurling steel roller and the extracting clamping rollers are in synchronous transmission connection through a transmission device; and the two ends of the knurling rubber roller are axially fixed with the fixing plates on two sides and cylinders are respectively connected with longitudinal horizontal front parts of the two ends of the knurling rubber roller.