In order to realize the efficient recovery of iron resources in red mud, taking the Bayer red mud from Guangxi as the material, the effects of calcination temperature, roasting time and CO volume fraction on the behavior of weak magnetic separation and iron extraction under the two schemes of “magnetization roasting-weak magnetic separation” and “high-intensity magnetic separation discarding tailings-concentrate roasting-weak magnetic separation” are compared. The results show that after pretreatment with 1 440 kA/m high-intensity magnetic separation discarding tailings, under the conditions of calcination temperature of 650 ℃, calcination time of 50 min, total gas flow of 500 mL/min and CO volume fraction of 30%, red mud is processed by “magnetization roasting-weak magnetic separation”, the iron concentrate with iron grade of 60.35% and recovery rate of 76.31% can be obtained and its combined yield and recovery are 48.93% and 60.83%, respectively. The strong magnetic separation pre-enrichment is obvious, and the magnetization roasting further reduces the weakly magnetic iron minerals in the red mud to strongly magnetic magnetite, which facilitates the recovery of iron by weak magnetic separation.