The utility model discloses an automatic reagent feeding device for lime dissolving tank, including feed arrangement and dissolving tank, the lime powder dissolves in belt conveyor input dissolving tank from feed arrangement. Feed arrangement includes the feed bin, and the top of this feed bin is equipped with relief valve and dust collector. Lime conveys in the dissolving tank fall into band conveyer under the broken hunch butterfly of pneumatics, the broken hunch of mechanical pears sword formula and multiple screw feeder's effect on. The built-in lime mixer of lower extreme of dissolving tank, the lime breast is prepared to the raceway fluming water under the effect of lime mixer in the dissolving tank. The lime breast is carried through the transfer line under the effect of solution feed pump and is added the snack made with traditional chinese medicines in corresponding. The utility model discloses it has following advantage to compare prior art: the utility model discloses an automatic reagent feeding device for lime dissolving tank, automatic feeding, stirring, transport lime breast, the operation of full automation procedure.