Firstly, simultaneous thermal analysis (TG-DSC) was employed to uncover the impacts of hematite-limonite and finely ground limestone on the oxidation process of magnetite. It was discovered that the decomposition and escape of calcium carbonate in limestone and the crystallization water in limonite inhibited the oxidation of magnetite. Subsequently, the influence mechanism of adding finely ground hematite-limonite on the oxidation kinetics of fluxed magnetite pellets under different ore blending conditions was emphatically studied. And the internal relationship between the oxidation degree of pellets and their roasting performance under the process conditions simulating the belt roaster was revealed. The results indicated that when the oxidation temperature was within the range of 850~1000℃, the pellets with different ratios of hematite-limonite were controlled by chemical reactions in the early stage of the oxidation reaction. It was also found that the higher the addition of hematite-limonite, the higher the apparent activation energy. Moreover, the apparent activation energy in the early oxidation stage of pellets with limonite added was higher than that of pellets with an equal amount of hematite added at the same basicity. The main reason for this was that the removal of crystallization water from the former pellets took away part of the heat and reduces the oxygen partial pressure during the heating process. Unlike the traditional grate kiln process, for the belt roaster, the oxidation degree of the pellets in the preheating stage was not necessarily the higher the better. When the oxidation degree of the pellets in the preheating stage was too high, it led to less heat being provided by the oxidation of Fe3O4 in the roasting stage, which was detrimental to the improvement of the pellets' strength.