To explore the mechanism and process of chemical looping depolymerization for cellulose in the presence of iron-based oxygen carriers, the characteristics of chemical looping combustion for cellulose at different heating rates were investigated by thermogravimetric analysis tests. The activation energy of cellulose during chemical looping combustion was calculated using chemical reaction kinetics and its kinetic mechanism was revealed. The microscopic reaction network of cellulose during chemical looping combustion was elucidated from the microscopic atomic scale by using ReaxFF MD simulation synthesis technique.The thermal analysis results show that the addition of iron-based oxygen carriers can reduce the onset temperature of cellulose chemical looping depolymerization and that the lattice oxygen released by iron-based oxygen carriers can help promote the chemical looping depolymerization of cellulose. Chemical looping combustion process of cellulose are divided into three different stages: volatile analysis out combustion, semi-coke conversion combustion and coke combustion stages.The kinetic model shows that the activation energy of cellulose in the thermal conversion process at different conversion rates is about 220-405 kJ/mol, with the highest activation energy of the reaction occurring at stage 3. Finally,ReaxFF MD simulations show that the overall chemical looping combustion process of cellulose follows the free radical chain reaction theory. The reactive radicals generated by cellulose cleavage reacted with the lattice oxygen releasing the oxygen carrier form intermediates such as 2-hydroxyacetone, which then under go further radical reactions to produce CO2. A complex reaction network for the release of CO2 production during the chemical looping depolymerization of cellulose in the presence of oxygen carriers is finally obtained.