Abstract: The magnetization roasting process is one of the effective ways to treat complex and refractory iron ores. However, energy and reducing agents are required during its production process. As a clean energy source, biomass can be thermally decomposed to produce CO, CO₂, CH₄, and H₂, among which CO, CH₄, and H₂ can be used as reducing agents in the magnetization roasting process of iron ore, achieving clean production. Using corn straw and hematite as raw materials, the thermal decomposition and gasification characteristics of straw biomass were investigated during magnetization roasting. Gas composition analysis results showed that under the magnetization roasting conditions of 700 ℃, N₂ flow rate of 300 mL/min, and straw-hematite mass ratio of 1∶3, the maximum production of CO_x reached 277.45 mL, indicating the optimal thermal decomposition effect of straw. TG−FTIR analysis results showed that hematite did not change the type of straw pyrolysis products, but altered the release characteristics and production of the products. In the magnetization roasting process above 800 ℃, the DTG curve exhibited a second weight loss peak, indicating a significant increase in the reaction rate of straw thermal decomposition during magnetization roasting.