The invention belongs to the field of ceramic products, and in particular relates to a Dehua ivory white porcelain and a preparation process thereof. The Dehua ivory white porcelain prepared by the present invention includes lard white body and lard white glaze, and the lard white body is made of Dehua kaolin, low-temperature clay, low-temperature stone, Dehua quartz, and pyrophyllite 18-25%. Made by comparison, the lard white glaze is made of low-temperature stone, pyrophyllite, Dehua Yangshan limestone, quartz, and Dehua kaolin. The Dehua ivory white porcelain provided by the present invention selects raw materials with large reserves and low prices as raw materials for lard white body and lard white glaze, and strictly controls the chemical components of the raw materials. Introducing trace amounts of rare earth elements cerium and praseodymium into the raw materials of the glaze can make the body and glaze appear milky yellow lard color, making the porcelain fine, dense, moist, lard color, soft in color, firm in white, and as white as fat , slightly yellow, has the closest artistic effect to traditional Dehua ivory white porcelain.