Abstract: Disclosed are molybdenum trioxide with a novel molecular structure and a chiral octahedral crystal phase structure, octamolybdate of the molybdenum trioxide and a preparation method of the octamolybdate. A molecular formula of ?-MoO3 with the novel molecular structure and the chiral octahedral crystal phase structure is Mo8O24, and the generated nano-molybdate based on the octamolybdate is a new species, so that a new member is added to inorganic salt chemical industry, and an application of the nano-molybdate changes all aspects of daily life of people, for example, the nano-molybdate having a disinfection function and insoluble in water is used in agricultural crop production and quality improvement, freshwater aquaculture and mariculture, sanitary disinfection, various anti-microbial and anti-tumor activities, batteries and various energy storages, semi-conductors, anti-biochemical weapons, intelligent materials and other aspects.