The outer cylinder of aircraft landing gear is often subject to complex alternating pressure and prone to different degrees of failure, so it is of great significance to explore the rapid repair process on site. In this paper, 15-5PH alloy powder was used to repair the inner surface, outer surface and hole structure of aircraft landing gear outer cylinder by laser cladding, and the mechanical properties of the repaired cladding layer were tested. Results show that when the laser power P=1 400 W, scanning speed Vs=0.36 m/min, powder feeding speed Vf=1.4 rad / min and overlap coefficient f=40%, the ideal cladding layer can be obtained. The microstructure of cladding layer is dense, the composition is uniform, and there is no obvious macro-segregation. Good metallurgical bonding can be obtained between the layer and the matrix interface. The imaging agent is used to detect the repair area of the outer cylinder, and there is no obvious defect in the repair area. The tensile strength, yield strength, elongation and impact toughness of the cladding layer all exceed 90% of the performance of the matrix, which meets the requirements of repairing applications.