To improve the wear resistance of YT tool steel, TiB2/TiN coating was prepared by laser cladding on its surface, and the influences of power parameters on microstructure and wear resistance were studied by experimental tests. Results show that the TiB2/TiN coating forms a compact structure which means the coating is closely bonded with the substrate. As the power increases gradually, the coating thickness also increases. Many small convex structures are formed on the coating surface area, and boundary layer is clearly observed. The deposition rate of TiB2/TiN coating increases linearly with the increase of power, from 2.63 nm/min to 6.64 nm/min, and the hardness of the coating continues to increase. The nanocomposite structure is formed between the h-BN structure and nanocrystalline TiB2. Higher cohesion energy is formed at the grain boundary, which improves the strengthening effect of grain boundary significantly. As the power is increased, both the friction coefficient and wear rate of TiB2/TiN coating increases first and then decreases. When the power is 2.0 kW, the friction coefficient rises to 0.79 that results in maximum wear rate of 4.75×10-6 mm3/(N·mm). This study has a significant theoretical guidence for improving the wear resistance and service life of YT tools.