In this article, the microwave magnetizing roast process of three kinds of Bayan Obo ore of different Fe-grades were studied experimentally, where microwave as the heat source and the activated charcoal as reductant. The reduction characteristics of hematite changed into magnetite by microwave magnetizing roast were studied analytically under different experimental conditions, where magnetisability and percent reduction of roasting ores as measure.It showed that under the optimum conditions of microwave roasting of hematite (the theoretical carbon content, the microwave voltage of 220V, the temperature of 650 °C and the heat preservation time of 10min), magnetisability and percent reduction of hematite were best , close to the theoretical value of 2.33 and 11.11% respectivly. And after the first weak magnetic separation of microwave roasting ores , the recovery of iron were all above 90%, which indirectly showed that the microwave reducing roasting magnetization effect were very good under the conditions. The Fe-grades of iron concentrate may achieve above 60% after the second magnetic separation ,which met the requirement of iron-making.