The invention belongs to the field of environmental chemistry, and in particular relates to inorganic anticorrosive pigment modified with zinc molybdate, and a modifying preparation method of the inorganic anticorrosive pigment. According to the modifying preparation method, the zinc molybdate is used as a modifying material, and a cyclic ultrasonic cavitation effect and high-temperature and high-pressure water bath thermal effect synchronous synergistic regulation process is adopted, so that a modified product system is more uniform in components and has a more stable effect; the ultrasonic-hydrothermal synergistic process solves the problem that the particle size and crystallization degree of nanocrystalline are difficult to regulate synchronously; a product is dried by using a spray drying way, so that the preparation efficiency is increased. The prepared zinc molybdate modified nano anticorrosive pigment has the advantages of being high in purity, complete in crystallization, uniform in particle size, good in dispersity, and the like; the salt water resistance of a paint film prepared from the modified inorganic anticorrosive pigment is 2-4 times that of a paint film prepared from unmodified inorganic anticorrosive pigment. The method has the advantages of simple process and low cost, thus being suitable for large-scale production.