The invention discloses an accurate rejecting device for a bag making
machine, which comprises a control element, a detection
assembly arranged above a feeding device, a buffer rack arranged between a turnover material turning device and an edge sealing device, a plurality of conveying rollers arranged on the buffer rack along a material conveying path, and a buffer rack rotatably mounted on the buffer rack, a
stroke feedback element used for detecting the overturning
stroke of the buffer frame is installed on a rotating shaft of the buffer rack, and the
stroke feedback element, the detection
assembly and the control element are in
signal connection. The detection
assembly is arranged on the feeding section, the rotation angle of the buffer frame is detected in real time, the self-adaptive rotation angle of the buffer frame in the material conveying process is obtained, and compensation calculation can be conducted on the length of materials conveyed between the detection assembly and the removing device according to the rotation angle of the buffer frame; according to the material detection device, the position detected by the detection assembly is ensured to be consistent with the
cutting position of the removing device, the comprehensiveness of material detection is ensured, meanwhile, errors caused by conveying are reduced, waste caused in the removing process is reduced, and the cost is saved.