Abstract: Chemical looping gasification is an innovative energy conversion technology with significant research and application value. As the demand for clean energy has surged in recent years, research in this field has delved deeper into biomass and coal gasification. To explore the mechanism and process of lignin chemical looping gasification in the presence of iron-based oxygen carrier. The chemical looping gasification process of lignin was simulated by ReaxFF-MD method with Fe2O3 as oxygen carrier. It was found that Fe-based oxygen carrier could promote the pyrolysis of lignin and provide lattice oxygen to enhance the conversion of tar and coke. The yield of CO and H2 and the pyrolysis gasification efficiency of lignin can be increased by increasing temperature. The increase of the molar ratio of oxygen carrier to biomass can promote the formation of CO, and obtain the synthesis gas with high yield when the ratio is 2.5, the synthesis gas yield is up to 47.65%. In addition, comparing the properties of nickel ferrite spinel and iron oxide, it was found that NiFe2O4 can provide more lattice oxygen for the lignin chemical looping gasification process, improve the hydrogen yield, facilitate the efficient and clean conversion of lignin to syngas, enhance the carbon conversion rate, and meet the current target requirements of carbon emission reduction.