Abstract: For the limitation of the single-pellet unreacted shrinking core model in studying a multi-pellet system, a mathematical model of iron oxide pellet reduction in an isothermal fixed bed was constructed based on the reduction behavior of single pellets. The analytical solution of the model was obtained by introducing dimensionless variables, and the characteristic line method was used for numerical analysis. At last the reduction experiments of the fixed bed consisted of multiple pellets were performed in a middle temperature tube furnace and the predicted results by the model agreed well with the measured ones by experiment.