The invention relates to a biological nanometer magnetic target anti-cancer drug, which is formed by coupled biological nanometer magnetic smalls and anti-cancer chemical drug. Wherein, the biological nanometer magnetic small is nanometer magnetic particle formed in magnetic bacterial cell, at 35-120nm diameter, while its main component is Fe3O4 or Fe3S4; single magnetic particle is packed by film; and the coupled anti-cancer chemical drug comprises chemotherapy drug, nucleic acid drug, radioactive nuclide or antibody drug. The invention also provides relative production that using physical adsorption couple or based on the active function group contained by smalls and anti-cancer drug, to select right coupler via chemical reaction to couple them. And the smalls has better bioavailability, less side effect, therefore, the anti-cancer drug can be accurately transmitted to ill part via external magnetic field, to reduce the contact between drug and normal organism., to realize target positioning treatment.