Abstract: In order to prepare ceramic reinforced Ni-base composite coating, chromium carbide Ni-base composite coating was prepared on the surface of 45# steel by laser cladding, the microstructure, phase structure and microhardness of the coating were studied. The shapes of chromium carbide ceramic particles were quadrangular, hexagonal and irregular block. By the analysis, quadrangular chromium carbide was Cr3C2, hexagonal chromium carbide was Cr7C3,the composition of irregular blocky chromium carbide was indeterminacy, may be Cr3C2 or Cr7C3.The microhardness of the coating was 3.5 times of the substrate. The coating had high microhardness and dense microstructure. The results indicated that the coating was mainly composed of Cr-Ni-Fe-C, C, Cr7C3 and Cr3C2.The microstructure of the composite layer was proved to be homogeneous and dense. A good metallurgical combination was formed at the boundary of the coating layer and substrate. The research plays a vital role in theoretical research and practical application of the in-situ synthesized chromium carbide Ni-base composite coating.