The invention relates to a fine-pottery sanitary ceramic body and a manufacturing method thereof and belongs to the technical field of ceramic products, which is used for reducing the deformation of a sanitary ceramic product and improving the quality of glaze. The fine-pottery sanitary ceramic body is characterized in that a body raw material comprises the following components in part by mass: 10 to 30 parts of ball clay, 30 to 60 parts of kaoline, 5 to 15 parts of porcelain clay, 5 to 15 parts of quartz and 5 to 15 parts of wollastonite, wherein the kaoline comprises 10 to 25 calcined kaoline. In the manufacturing method, the raw materials and the adding proportion of the fine-pottery body are preferably selected, the crystal phase content of mullite, quartz and the like is controlled, and the glass phase content and the high-temperature plastic deformation are reduced so as to fulfill the aim of reducing the deformation of fine-pottery sanitary ceramics; while reducing the hygroscopic expansion of the body, the manufacturing method improve thermal expansion coefficient of the body at the temperature of 200 DEG C to make the glaze bear high compressive stress, thereby improving the anti-cracking performance of products and ensuring enough long service life. Through the refinement of slurry granularity, the method remarkably reduces the occurrence of disadvantage of glaze pinholes, does not need to reduce the pinholes by using engobe, simplifies a production process, and improves the production efficiency and the qualification rate of the products.