NiAlBSi high-temperature alloy coatings are prepared by laser cladding on the 45# medium steel. The microstructures and properties of the NiAlBSi alloy coatings obtained at different scanning velocities are investigated by means of X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that all coatings consist of Ni-Al dendrites. With the increase of scanning velocity, the hardness values of the coatings increase gradually due to the refinement of dendrites, while the wear resistance and the high temperature oxidation resistance present the trend of first increasing then decreasing, and the highest values are obtained at the scanning velocity of 4 mm/s.