Abstract: To solve the problem that the micro-mechanism of self-healing of microencapsulated asphalt is not clear, microcapsules of corn oil were prepared by in situ polymerization, the core content was determined using petroleum ether immersion method and the stability was verified. A fluorescence microscope was used to observe the morphology characteristics of microcapsules, and a scratch self-repair experiment of corn oil microcapsule asphalt was designed to observed the self-repair behavior. The micro-characteristic parameters of self-healing asphalt were obtained based on atomic force microscope test, and the influence of microcapsules on self-healing asphalt was quantitatively analyzed. Results show that the wall material of the prepared corn oil microcapsules is stable, with a core content of 52%. The corn oil microcapsules have irregular spherical structure, and the particle size distribution is mainly between 0 and 30 μm, with an average particle size of 23.7 μm. The microcapsule after the scratch stress breaks and releases the corn oil regenerant, which diffuses through capillary action and fills the crack to achieve self-healing of asphalt. The average area of peak structure on the surface of 4% and 8% microcapsule asphalt samples is reduced by 17% and 27%, respectively, with the repair rates 36% and 41%, respectively. The addition of corn oil microcapsules reduces the influence of aging on the microscopic parameters of the asphalt surface, and the aging asphalt is repaired to a certain extent. The corn oil microcapsules can change the content of aging asphalt components, achieving "performance regeneration" of aging asphalt and providing scientific basis for preventive maintenance of asphalt pavement.