The utility model relates to the technical field of constant-temperature water bath devices. The utility model discloses a constant-temperature water bath device for enzymolysis of chitosan. Box body,bases are fixedly mounted at four corners of the bottom of the box body; a box cover is arranged at the top of the box body; a handle is fixedly installed in the middle of the top of the box cover, an electric cabinet is fixedly installed on the side, located on the back face, of the top of the box body, cooling fans are fixedly installed on the two sides of the electric cabinet, the bottom of aninner cavity of the box body is fixedly sleeved with a heating rod, L-shaped rods are fixedly installed in the middles of the two sides of the inner cavity of the box body, and the tops are hinged tofolding blocks. The utility model discloses a constant-temperature water bath device for enzymolysis of chitosan. According to the constant-temperature water bath device, the folding blocks and the sleeve blocks are arranged, when substances need to be hydrolyzed, the sleeve blocks are fixed through the folding blocks, and therefore the fixing box placed in the box body can be firmly fixed, and compared with an existing constant-temperature water bath device, when the substances are hydrolyzed, the device can firmly fix the substances needing to be hydrolyzed, and the hydrolysis efficiency isimproved.