The present invention relates to a lime slaker belonging to the technical field of calvital producing device. The lime slaker comprises a first digestion device, a second digestion device, a third digestion device, a spray device, a dust removing device, a first power mechanism composed of a first motor and a first speed reducer, a second power mechanism composed of a second motor and a second speed reducer and a third power mechanism composed of a third motor and a third speed reducer, wherein the first digestion device comprises a first box body and a pair of first stirring shafts; the second digestion device comprises a second box body and a second stirring shaft; the spray device is arranged at the top part of one side of the first box body; the dust removing device is arranged at the top part of the other side of the first box body; the first speed reducer taking the first motor is connected with the first stirring shafts; the second speed reducer taking the second motor is connected with the second stirring shaft; and the third speed reducer taking the third motor is connected with the third stirring shaft. The occupation area is saved, and the dry powder calvital quality is improved. The driving efficiency is improved, and noise is effectively controlled.