Belonging to the technical field of biomass carbonization, the invention relates to a stirring type biomass carbonization furnace, which comprises a furnace body, a combustion chamber, a preheating bin, carbonization chambers, gas guide pipes, a chimney and an upper cover disposed in the furnace body. The preheating bin is arranged above the carbonization chambers, and the combustion chamber is arranged below the carbonization chambers. An auger is disposed in the preheating bin. A material lead-in channel is arranged between the preheating bin and the carbonization chambers, a plurality of gas guide pipes are disposed between the carbonization chambers and the combustion chamber, and the carbonization chambers are internally equipped with stirrers. According to the invention, by means of stirring, the heat transfer mode is changed, and the material heating speed is fast. By stirring the heated high temperature materials with lower temperature materials to blend them together, the heat transfer area between the materials is greatly increased. Because of material movement, convection heat transfer can be generated, the heating can be uniform, and the quality is good. The flammable gas generated by thermal cracking carbonization can combust directly in the furnace, and provides enough heat for thermal cracking at the middle and later stage of carbonization. No additional fuel is needed, thus achieving an energy-saving effect.