The invention relates to an 
antibody-coupled bionic immune 
magnetic sphere and a preparation method of the 
antibody-coupled bionic immune 
magnetic sphere, belonging to the technical field of nanometer materials. According to the bionic immune 
magnetic sphere, the water-soluble Fe3O4 nanocluster is taken as the core, a 
cell membrane coats the core, and an 
antibody with a modification group is bonded outside the 
cell membrane through covalent 
coupling. The preparation method of the antibody-coupled bionic immune magnetic sphere comprises the following steps: preparing the Fe3O4 nanocluster, namely, MNC; preparing 
cell membrane fragments modified by 
choline azide, namely, M; reacting MCN and M to obtain a bionic magnetic sphere, and reacting the modification group with the antibody to obtain the antibody with the cyclo-ethynylation modification group; and 
coupling bionic magnetic sphere solution and the antibody with the cyclo-ethynylation modification group, thus obtaining the bionic immune magnetic sphere provided by the invention. The bionic immune magnetic sphere is good in dispersibility, rapid in 
magnetic response, and high in identifying efficiency when used for capturing 
tumor cells, no white blood cells exist in the background, and the captured 
tumor cells are good in activity. For the preparation method, the raw materials are easily available and have universality in the construction of the bionic immune magnetic sphere.