The invention discloses a preenrichment-three segment suspension roasting-magnetic separation treatment method of complex refractory iron ores, and belongs to the technical field of mineral processing. The method comprises the following steps: 1, levigating the complex refractory iron ores, carrying out weak magnetic separation, and carrying out strong magnetic separation on mine tailings; 2, putting concentrate obtained after strong magnetic separation in a suspension roasting furnace, and heating to 450-800DEG C in a suspension state in order to carry out pre-oxidation roasting; 3, introducing nitrogen to displace air, and introducing a reducing gas to carry out reduction in a suspension loose state; 4, introducing air when the temperature decreases to 250-400DEG C in order to oxidize, taking out the obtained material when the temperature decreases to below 100DEG C, and carrying out ore milling; and 5, carrying out third segment magnetic separation, and mixing concentrate obtained after three segment magnetic separation with concrete obtained after the weak magnetic separation to obtain finial concentrate. The method has the advantages of simple process, improvement of the recovery rate of the complex refractory iron ores, strong adaptability, safe and reliable process, uniform and stable product quality, energy saving and consumption reduction.