Abstract: A rotary furnace comprises a roller (2), a feeding end of the roller (2) being higher than a discharge end of the roller (2), and also comprises: a feeding device (1), communicated with the feeding end of the roller (2) in a way of rotary seal; a discharge device (6), communicated with the discharge end of the roller (2) in a way of rotary seal; a driving device, arranged outside the roller (2) and used for driving the roller (2) to make reciprocating oscillation around the rotating axis thereof; a support device, arranged outside the roller (2) and used for rotating and supporting the roller (2); a control device, connected to the driving device by a lead and used for controlling the radian of the reciprocating oscillation of the roller (2).