The invention belongs to a preparation method of organic-inorganic material composite modified cement, belonging to the technical field of building material preparation. The cement is elaborately prepared from common materials by using an organic-inorganic composite technology, and uniformly stirring and mixing. The cement has special structure and property characteristics; and the prepared organic-inorganic material composite modified cement which is short in settling time and high in strength is prepared. The cement prepared by using the technology is short in flocculation time and good in strength, can be quickly cemented, meets relatively good strength requirements, and can be widely applied to building fields such as channel construction and underwater construction.