Abstract: Taking six kinds of iron ore powder of Australian mine, Brazilian mine, King powder mine, Newman mine, Zhangzhuang mine and Gushan mine as raw materials, the fluidized experiment was carried out through the hot visible fluidized bed. The bonding state of six kinds of reduced iron ore powders, under the condition of coated and uncoated carbon powder was studied. The results show the coated carbon powder can improve the fluidization state of the six kinds of iron ore powders. Among them, the bonding ratio of Brazilian mine, Newman mine and King powder mine decreases obviously, and the fluidization state was good; Under the condition of uncoated carbon powder, the surface of iron ore powder forms slender iron whiskers, which are connected to each other and lead to the binding of iron ore powder. Under the condition of coated carbon powder, the surface of iron ore powder forms fine nano-scale metal spheres, which can inhibits the formation of iron whiskers and reduce the adhesion between the iron ore powder.