The invention relates to a production process of unfired building ceramic. The production process comprises the following steps: (1) drying and dehydrating: drying and dehydrating gypsum to obtain semi-hydrated gypsum; (2) carrying out compression moulding: mixing the semi-hydrated gypsum with water in a mass ratio of 100 to (6-25) and quickly stirring uniformly, and then carrying out compression moulding to obtain ceramic blanks; (3) soaking in water to hydrate: overlying the obtained ceramic blanks which are separated by cotton cloth, putting the ceramic blanks into a hydrating slot, and putting the overlaid ceramic blanks and the hydrating slot under a press, applying pressures by virtue of the press, maintaining the pressure unchanged, introducing water into the hydrating slot and soaking the ceramic blanks for 1-3 hours; and (4) naturally drying. By using gypsum as a raw material, the production process of unfired building ceramic is low in production cost, simple in process and free of high-temperature firing and has better energy conservation and emission reduction effects, and the prepared unfired building ceramic is good in performance.