The lime digester is mainly composed of power device, filter screen, rolling ring, cylinder (outer cylinder and inner cylinder), tooth ring, wheel support device, etc. The inside of the cylinder is arranged into four areas, which are buffer zone, digestion zone, homogenization zone and milk residue separation zone, and the tail is provided with dregs and non-slag devices. The main feature of the lime digester is that it adopts the method of ashing by moving instead of stirring. The rear of the lime digester is provided with a screen. Lime block contact with water in the simple water absorption and digestion, lime milk through the sieve from the discharge outlet, the undigested burnt and raw lime by the outer cylinder tail dregs device discharged out of the cylinder, the chemical plane mechanism is reasonable, easy to operate, high production efficiency, large production capacity, low labor intensity, applicable to any quality of lime.