A communication method and a device are described to compress and decompress a data packet including an ethernet header to reduce radio transmission resources of an air interface. The communication method includes determining, by a sending device, a to-be-sent data packet. The to-be-sent data packet is a data packet including an ethernet header. The method further includes determining, by the sending device, a field to be compressed in the header of the to-be-sent data packet; and compressing, by the sending device, the header of the to-be-sent data packet according to a preset method. The preset method includes: removing the field to be compressed from the header of the data packet, or replacing the field to be compressed with a corresponding short field; and sending, by the sending device, a data packet obtained after the compressing.