Automatic feeding device

The utility model discloses an automatic feeding device which comprises a machine frame, a chain transmission assembly arranged on at least one side of the machine frame, a first tray and a second tray, wherein the first tray and the second tray are arranged on the two sides of the machine frame in a lifting mode respectively. A first pulley assembly is connected between the chain transmission assembly and the first tray, and a second pulley assembly is connected between the chain transmission assembly and the second tray. The chain transmission assembly firstly pulls the first tray to ascend along the rack through the first pulley assembly until the material containing box on the uppermost layer reaches the feeding position for feeding; the material containing box on the uppermost layer becomes an empty material box and then is placed on the second tray, the first tray continues to ascend by the height of the material containing box, and meanwhile the chain transmission assembly drives the second tray to des