The invention discloses a preparation method for daunorubicin and 5-bromotetrandrine co-carried magnetic ferrosoferric oxide nanoparticles, and relates to a preparation process for magnetic drug-loaded nanoparticles. The method comprises the following steps: dissolving ferric sulfate, ferrous sulfate in water according to a certain ratio; adding ammonia water in the presence of nitrogen, and further adding oleic acid; carrying out steps of vigorous stirring, high temperature aging and the like to obtain oleic acid coated ferrosoferric oxide nanoparticles; modifying the resulting ferrosoferric oxide nanoparticles through a proper amount of PluronicF127 to obtain the blank magnetic ferrosoferric oxide nano-carrier; adding the blank magnetic ferrosoferric oxide nano-carrier to a methanol solution comprising daunorubicin and 5-bromotetrandrine, then carrying out steps of vigorous stirring overnight, washing through the water, and magnetic separation to obtain the daunorubicin and 5-bromotetrandrine co-carried magnetic ferrosoferric oxide nanoparticles.