Abstract: Based on the research of the influence of fluxing agent kinds,dosage on the deep reduction,current situation and progress of fluxing agent,kinetics and thermodynamics of fluxing agent in the reduction system were stated in this paper.It was showed that calcium-based and sodium-based fluxing agent were used,which was added into the reducing deep reduction of low grade unwieldy iron ore,could improve the reaction rate for Fe₂O₃ reducing to Fe₃O₄ and educe or avoid the generation of ferric silicate,which was more difficult to reduce.All of this could decline the system reduction temperature and benefit the increase of iron grain size.Difference of fluxing action existed between these two kinds of fluxing agent with different reaction temperature and iron ore properties.