In order to develop a new MAX phase composite coating on the surface of TC4 titanium alloy, a Ti-Al-N composite coating containing Ti2AlN MAX phase was synthesized on the surface of TC4 titanium alloy by laser cladding. The structure characteristics and hardness distribution of the coating were analyzed, and the in-situ synthesis mechanism of the composite coating was studied. The results indicate that the coating and the substrate after powder cladding with different ratios of amount of substance show a good metallurgical bond. The coating is mainly composed of TiAl matrix, Ti2AlN MAX phase, and TiN dendrites. The average hardness of the coating is about twice that of the substrate. The coating thickness is between 1mm~1.6mm. Adding a small amount of Al powder can promote the reaction of TiN and TiAl in the molten pool, thereby significantly increasing the content of Ti2AlN MAX phase in the coating. The research results are of great significance to the preparation of MAX phase composite coatings by laser cladding technology based on the clarification of the MAX phase in-situ synthesis mechanism.