The work aims to study the microstructures and wear resistance of laser cladding coating on Ti811 alloy surface. A Ni-based composite coating reinforced by in situ synthesized TiC and TiB2 was prepared on Ti811 by laser cladding. Phase, mi-crostructure, microhardness and wear resistance of the cladding coating were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microscopic analyzer (EPMA), Vickers hardness tester, and friction wear testing ma-chine. Moreover, the refinement mechanism of TiC was also discussed by the two-dimensional lattice misfit theory. A good metal-lurgical bonding was formed between the laser cladding coating and substrate, the main phase composition of the cladding coating included TiC, TiB2, Ti2Ni and γ-Ni, of which TiC was equiaxial dendrite and petal shape, and the two-dimensional lattice misfit between the face (001) of Y2O3 and the face (110) of TiC was 6.813%, which indicated that Y2O3 as the heterogeneous nuclei of TiC was middle-effective. The average microhardness of the cladding coating was 913.93HV0.5, about 2.4 times than that of the substrate. The friction coefficient of the cladding coating kept stable between 0.45 and 0.52, and the main wear mechanisms were adhesive wear and abrasive wear. The Ni-based composite coating can be successfully prepared by laser cladding technology on Ti811 alloy surface. Y2O3 particles in the cladding coating have the effects to strengthen fine crystal, reinforce dispersion and in-crease nucleation rate. Meanwhile, microhardness and wear resistance of the cladding coating are increased dramatically.