The water bath box comprises a water bath box body, a control surface is installed at the position, close to the bottom end, of the front face of the water bath box body, the top end of the water bath box body is open, a cover plate is clamped at the top end of the water bath box body, and an isolation
assembly is arranged at the position, close to the bottom end, of an inner cavity of the water bath box body. The isolation
assembly comprises a limiting
flange, a partition plate and a through hole, a
test tube rack is placed on the top end face of the partition plate, and the
test tube rack is used for storing specimen test tubes; the holding rod and the connecting
rope are matched with the first hook and the second hook, so that when a sample needs to be taken out, a worker only needs to hold the holding rod and lift the holding rod upwards, the
test tube rack can be lifted from water in the water bath box body, and the test tube rack can be stably hung after the test tube rack comes out of water by matching with the second hook; therefore, the test tubes on the test tube rack can be conveniently taken out to observe specimens.