A water bath hardening method using a water bath device for tomographically plastinated specimens, wherein comprising a water bath box, a control box provided in the water bath box, heating tubes, a water circulation assembly, and positioning grids, wherein the upper surface of the water bath box is open, the heating tubes are provided inside the water bath box, the heating tubes are electrically connected to the control box, the water circulation assembly comprises a water circulation pipeline, a circulating water pump provided on the water circulation pipeline, and a drain outlet provided on a side wall of the water bath box, and the two sides of the inner walls of the water bath box are provided with positioning grids opposite each other; the water bath hardening method comprises following steps: a. dehydrating a plastinated slice, then putting it in a vertical embedding box; b. pouring liquid medicine into the vertical embedding box, and putting it in a vacuum box for vacuum infiltration; c. vertically inserting, after the infiltration is completed, the vertical embedding box between positioning grids in the water bath box, and carrying out water bath hardening by means of the water bath box; and d. taking out, after the liquid medicine is completely polymerized, the plastinated slice from the vertical embedding box; characterized in that the step a comprises: coating a sealing strip on the surface of one piece of tempered glass, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner; and inserting the plastinated slice between the two pieces of tempered glass from the open upper end or placing the plastinated slice on the surface of one piece of tempered glass; coating the surface of the tempered glass around the plastinated slice with a sealing strip, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; and fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner. a. dehydrating a plastinated slice, then putting it in a vertical embedding box; b. pouring liquid medicine into the vertical embedding box, and putting it in a vacuum box for vacuum infiltration; c. vertically inserting, after the infiltration is completed, the vertical embedding box between positioning grids in the water bath box, and carrying out water bath hardening by means of the water bath box; and d. taking out, after the liquid medicine is completely polymerized, the plastinated slice from the vertical embedding box; characterized in that the step a comprises: coating a sealing strip on the surface of one piece of tempered glass, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner; and inserting the plastinated slice between the two pieces of tempered glass from the open upper end or placing the plastinated slice on the surface of one piece of tempered glass; coating the surface of the tempered glass around the plastinated slice with a sealing strip, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; and fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner. coating a sealing strip on the surface of one piece of tempered glass, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner; and inserting the plastinated slice between the two pieces of tempered glass from the open upper end or placing the plastinated slice on the surface of one piece of tempered glass; coating the surface of the tempered glass around the plastinated slice with a sealing strip, and providing two pieces of tempered glass opposite each other through the sealing strip to form a flat vertical space with one open upper end and the other three sides sealed; and fixing the surrounding three sides of the two pieces of tempered glass by fixing clips in an assisted manner.