The invention provides a stirring device. The stirring device comprises a stirring barrel, wherein the stirring barrel is divided into an ash discharging region, a convection mixing region and a water feeding region from top to bottom in the height direction; an ash discharging opening is formed in the top of the ash discharging region; the convection mixing region is provided with a slurry outlet; the water feeding region is provided with a water inlet; the water inlet is positioned in a side wall of the lower end of the stirring barrel; a plurality of groups of stirring fins are further arranged in the stirring barrel; rotating shafts of the different groups of the stirring fins are coaxial; the uppermost group of stirring fins are forward spinning stirring fins while the rest groups of stirring fins are reverse spinning stirring fins; the forward spinning stirring fins are positioned in the ash discharging region; and the reverse spinning stirring fins are positioned in the water feeding region. Compared with the prior art, the stirring device has the advantages that the forward spinning stirring fins and the reverse spinning stirring fins are designed in the stirring barrel, the convection mixing region is formed between the forward spinning stirring fins and the reverse spinning stirring fins, in a rotating process, the forward spinning stirring fins accelerate sinking of cement ash, the reverse spinning stirring fins increase water feeding speed, therefore, deposited large particles are reduced, and the strong convection mixing region is formed nearby the slurry outlet.