A visual identification-based full-automatic flange labeling machine, comprising a pneumatic chuck, a rotation mechanism, a linear push mechanism, a visual identification system, labeling actuators, a return-to-zero limiting mechanism, a workbench, and a controller, wherein the visual identification system, the labeling actuators and the linear push mechanism are all fixed to the workbench; the pneumatic chuck is connected to the rotation mechanism, and is used for fixing a flange; a first detection unit is provided on the pneumatic chuck and is configured to detect whether the flange is mounted on the pneumatic chuck, when the first detection unit detects that there is a flange mounted on the pneumatic chuck, the pneumatic chuck is configured to automatically clamp and fasten the flange; the rotation mechanism is connected to the linear push mechanism, and is used for rotating the flange on the pneumatic chuck; the linear push mechanism is configured to make a linear reciprocating motion, and is used for pushing the flange to/out of a labeling position; when the linear push mechanism arrives at the labeling position, the visual identification system is configured to detect the flange and identifie an initial label position on the flange; the labeling actuator is configured to avoid the initial label position through the rotation of the rotation mechanism, and the labeling actuator is used for printing a new initial on the flange; the linear push mechanism is disposed with the return-to-zero limiting mechanism which is used for limiting, after labeling completion, the pneumatic chuck after the pneumatic chuck returns to zero to be reset; a second detection unit is arranged between the linear push mechanism and the pneumatic chuck and is used for detecting whether the pneumatic chuck returns to zero to be reset, so as to control the return-to-zero limiting mechanism to automatically limit the pneumatic chuck; and the controller is used for controlling operation of the pneumatic chuck, the rotation mechanism, the linear push mechanism, the visual identification system, the labeling actuators, and the return-to-zero limiting mechanism. the visual identification system, the labeling actuators and the linear push mechanism are all fixed to the workbench; the pneumatic chuck is connected to the rotation mechanism, and is used for fixing a flange; a first detection unit is provided on the pneumatic chuck and is configured to detect whether the flange is mounted on the pneumatic chuck, when the first detection unit detects that there is a flange mounted on the pneumatic chuck, the pneumatic chuck is configured to automatically clamp and fasten the flange; the rotation mechanism is connected to the linear push mechanism, and is used for rotating the flange on the pneumatic chuck; the linear push mechanism is configured to make a linear reciprocating motion, and is used for pushing the flange to/out of a labeling position; when the linear push mechanism arrives at the labeling position, the visual identification system is configured to detect the flange and identifie an initial label position on the flange; the labeling actuator is configured to avoid the initial label position through the rotation of the rotation mechanism, and the labeling actuator is used for printing a new initial on the flange; the linear push mechanism is disposed with the return-to-zero limiting mechanism which is used for limiting, after labeling completion, the pneumatic chuck after the pneumatic chuck returns to zero to be reset; a second detection unit is arranged between the linear push mechanism and the pneumatic chuck and is used for detecting whether the pneumatic chuck returns to zero to be reset, so as to control the return-to-zero limiting mechanism to automatically limit the pneumatic chuck; and the controller is used for controlling operation of the pneumatic chuck, the rotation mechanism, the linear push mechanism, the visual identification system, the labeling actuators, and the return-to-zero limiting mechanism.