Multi-diameter vascular system was studied to realize the multi-point self-healing of the scratch on the surface of composite material. The main pipeline， secondary pipeline and micro-nano porous structure were embedded in the superficial part of the coating to form the multi-diameter microvascular healing agent delivery system. The research indicated that three-diameter microvasculature system had the best effect of conveying repair agent， and the diffusion of repair agent was more uniform and faster. The horizontal layout of the main pipeline could prevent the pipeline from blocking， and the delivery of the repair agent was more smooth. The main pipeline was embedded in the substrate， which could reduce its impact on the coating performance. Further study on micro-nano porous structure showed that the diversion network was better than that of the porous nickel foam. Therefore， the three-diameter micropipette system， which was embedded the main pipe horizontally into the substrate and used the guide net structure micro-nano porous structure ， was expected to be applied to the self-healing of the scratch on the surface of composite material.