The invention relates to a two-stage quicklime slaker, which comprises: a feed inlet, a sealed conveying section box, a first slaking section box, a water sprayer, a sealed dust hood, an upper slaking box blanking part and a poke port, a second slaking section box, and a discharge port. Specifically, the first slaking section box is internally equipped with a pair of first stirring shafts with stirring blades, the pair of first stirring shafts are driven by a first driving device and have opposite rotation directions. In addition, the second slaking section box is internally equipped with a pair of second stirring shafts with stirring blades, the pair of second stirring shafts are driven by a second driving device and have opposite rotation directions. And the sealed dust hood has a dust collection external port.