The invention provides a drying and quality improving device for low rank coal, and belongs to the technical field of coal drying. The drying and quality improving device comprises a machine body, a feeding hopper, a drying and heating device and discharge pipes, wherein the feeding hopper is arranged on the machine body; the drying and heating device is arranged in the machine body and is used for drying coal; the discharge pipes are arranged on the machine body and are used for discharging dust; and a suction device used for sucking dust into the discharge pipes is arranged in the machine body. By the adoption of the drying and quality improving device for low rank coal, dust is cleaned synchronously in the processes of feeding and drying, and dust is prevented from adhering to coal, sothat the coal quality is greatly improved.