The invention relates to a milling device comprising an abrasive disc shell (4), a feed port (1) and a discharge port (5). A first abrasive disc (81) and a second abrasive disc (82) are arranged in the abrasive disc shell (4). A main drive device is arranged on one side of the abrasive disc shell (4), and same-direction rotation or opposite-direction rotation of the first abrasive disc (81) and the second abrasive disc (82) is achieved through the main drive device. A high-pressure gas removal device (9) is arranged on the other side of the abrasive disc shell (4) to remove accumulated materials on the first abrasive disc (81) and the second abrasive disc (82).