The utility model provides a safety pin badge flaw detection system based on machine vision, including transport module, detection module and rejection module, the transport module includes conveyer belt and the PLC controller that is used for controlling the conveyer belt operation, detection module includes image processing unit, set up the camera bellows structure on the conveyer belt and be located the industrial camera machine of camera bellows structure, and the camera bellows structure is equipped with entry and export, and the interlude of conveyer belt runs through the entry and the export of camera bellows structure, and image processing unit is connected with industrial camera machine, PLC controller respectively, the rejection module is connected with the PLC controller by being located the export of camera bellows structure for release the conveyer belt with the safety pin badge inferior that detection module discerned. The utility model discloses a serious inconsistent badge of those sticker patterns is discerned to the industrial camera machine to reject badge inferior, only remain good badge, realized the good and bad badge of quick resolution and the target carrying out badge inferior to reject.