The surface of Q235 steel were prepared Fe-based laser cladding layers with different powder feeding rates. Microstructure morphology was studied by OM, SEM and EDS. The results show that with the increase of powder feeding rate, the carbide in the heat affected zone aggregates into blocks and the corrosion resistance decreases. The cladding layer is composed of planar crystals, coarse columnar crystals, columnar dendrites, dendrites, and equiaxed crystal. With the increase of powder feeding rate, in the bottom layer, the area of coarse columnar crystals decreases and the shape changes into columnar dendritic crystal and dendritic crystal. In the middle layer, the microstructure is refined and changes to equiaxed crystal rapidly. In the top layer, equiaxed crystal size decreases sharply. The dendrites are composed of Ni-enriched austenite, and intercrystal is composed of skeleton-like eutectic which is composed of carbides, ferrite, and martensite rich in Cr and Mo. The data for the microstructure morphology change principle of the laser cladding layer will be added.