The utility model discloses a heating device with automatic scale removal. In the heating device, two ends of a fire tube (2) are provided with seal heads; a scale-removing device is sheathed at the outsides of the fire tube (2) and a smoke tube (3) and consists of a screw (7) and scrapping plates (8), wherein the scrapping plates (8) are fixedly connected, and the scrapping plate (8) adjacent to the screw (7) is fixedly connected with a nut (9) sheathed on the screw (7); and a motor (10) drives the screw (7) so as to drive the scrapping plates (8) to do reciprocating movement along the outer walls of the fire tube (2) and the smoke tube (3). In the utility model, by the reciprocating movement along the outer walls of the fire tube and the smoke tube of the scrapping plates driven by the motor in the sale-removing device, the sales formed on the outer walls of the fire tube and the smoke tube are removed, without the needs of blowing out a furnace and dismantling the device, thus not only prolonging the service life of the heating device, but also guaranteeing the heating effect, improving production efficiency, saving time and labor, and resolving the problem that the original heating device can not remove scales automatically.