The invention discloses a sprocket pushing mechanism for an automatic chain grinding machine. The sprocket pushing mechanism comprises a motor, a transmission gear, a rocking rod, a rocking rod shaft, a screw pin, a sprocket pushing claw, a limiting block, a grinding position regulating handle, a sprocket pushing position regulating handle and a casing, wherein the motor, the rocking rod shaft, the grinding position regulating handle and the sprocket pushing position regulating handle are respectively mounted on the casing; the transmission gear is mounted on a motor shaft and meshed with fan-shaped teeth of the rocking rod; the rocking rod is mounted on the rocking rod shaft in a rotating manner; the sprocket pushing claw is mounted on the rocking rod in the rotating manner through the screw pin; the rocking rod is fixedly connected with the limiting block; the grinding position regulating handle and the sprocket pushing position regulating handle are respectively corresponding to the limiting block; the sprocket pushing claw is provided with a blocking bevel,a sprocket pushing arc and a screw pin mounting hole, and the screw pin is mounted in the screw pin mounting hole in a sleeved manner. The sprocket pushing mechanism disclosed by the invention is further provided with a sensing and detecting switch for a left sprocket shape and a right sprocket shape, and the sensing and detecting switch for the left sprocket shape and the right sprocket shape is arranged exactly opposite to a saw sprocket at the sprocket pushing position. The sprocket pushing mechanism disclosed by the invention is simple and reasonable in structure, good in rigidity, high in positioning accuracy and simple in regulating manner and can automatically identify the saw sprocket.