The invention discloses a glaze spraying device for a closestool water storage tank and belongs to the technical field of ceramic production equipment. According to the technical scheme, the glaze spraying device is characterized by comprising a liquid storage tank, wherein an installation barrel is arranged on the upper portion of the liquid storage tank, the liquid storage tank is provided with an anti-splashing sleeve, and the upper end of the anti-splashing sleeve is higher than the lower end of the installation barrel; the side wall of the installation barrel is provided with a plurality of first spray nozzles in the vertical direction, the upper side of the installation barrel is provided with a fixing seat, the fixing seat is provided with a plurality of second spray nozzles, and all the first spray nozzles and the second spray nozzles are matched to perform glaze spraying on the inner wall of a blank body; all the first spray nozzles and the second spray nozzles are in communicating connection with a glaze spraying pump on the outer side of the liquid storage tank through pipelines, and the liquid feeding end of the glaze spraying pump extends into the liquid storage tank; and the outer wall of the installation barrel is connected with an installation plate in the vertical direction through a pressing mechanism, and the position, close to the end outer wall, of the free end of the installation plate is provided with a plurality of flattening scrapers in the vertical direction. The glaze spraying device for the closestool water storage tank provided by the invention is convenient to use and good in effect and is used for glazing the blank body.