The invention relates to a magnetic persimmon tannin composite adsorption material and a preparing method thereof.According to the material, persimmon tannin serves as a main adsorption functional component, nanometer Fe3O4 particles serve as a magnetic functional component, and materials suck as chitosan and graphene can be selected as a loading (or cross linking) matrix of the adsorption component and the magnetic component.Magnetic nanometer particles are loaded on the surface of the matrix material with a reversed phase suspension method; solidification of persimmon tannin on the matrix material is achieved through a cross-linking reaction.The materials such as graphene, and the persimmon tannin material are used in combination, and thus a remarkable synergistic promoting effect is achieved on the adsorption performance of the magnetic persimmon tannin composite adsorption material; the material has very good adsorption capability on heavy metal ions, and can be applied to removal of heavy metal ions under the special conditions such as fluid pipeline dead corner retention and containers with complex shapes due to the paramagnetic property of the material.The material has the advantages of being high in stability and environment withstanding capability, high in yield, low in cost, extremely high in adsorption capacity, easy to separate and recycle, free of secondary pollution and the like.