The invention discloses a drum reactor. The drum reactor comprises a horizontal barrel body consisting of an inner barrel and an outer barrel, and has the characteristic that a detachable front end head and a detachable rear end head are arranged on the two ends of the inner barrel, wherein an inner barrel supporting rod which is movably matched with the inner barrel and a transmission mechanism for rotating the inner barrel are movably arranged on the peripheral wall of the inner barrel; an outer barrel supporting rod is fixedly arranged on the peripheral wall of the outer barrel; a spiral propeller for mixing and forwards propelling materials is arranged on the inner surface of the inner barrel; the bottoms of the front end head and the rear end head are respectively fixedly provided with an end head supporting rod; a first sealing device is arranged between the front end head and the inner barrel; and a second sealing device is arranged between the rear end head and the inner barrel. The drum reactor has the advantages that the structure is simple, the operation is convenient, continuous charging and discharging can be realized, and temperature of each point in the reactor can be effectively controlled.