The work aims to prepare a self-healing coating and evaluate and analyze the self-healing mechanism and self-healing efficiency of the coating. After prepolymerization in nitrogen atmosphere by prepolymer method, polycaprolactone and isophorone diisocyanate were added with disulfide chain extender and crosslinking agent and then the product was mixed with solvent such as antifoaming agent and leveling agent to obtain polyester type polyurethane self-healing coating. FTIR and Raman spectroscopy were used to characterize the chemical structure. The adhesion and hardness were measured by the Baige test and the Shore hardness tester. The self-healing properties of the coating, mainly expressed in self-healing time at different temperature, different damage levels and different thicknesses were recorded by three-dimensional video microscope and photographing. The thermal properties of the samples were characterized with thermogravimetric analyzer. The characteristic peaks of the S—S bond at 510 cm-1 and the C—S bond at 640 cm-1 were clearly visible, with adhesion of Grade I and Shore hardness of 73. The self-healing rate was accelerated with the increase of temperature from 300 min at room temperature to 5 min at 100 ℃. The effectiveness of self-healing was also affected by coating thickness and damage degree. The thermal stability of the coating increased with increasing degree of cross linking and the thermal decomposition temperature of all coatings was higher than 334.6 ℃. The disulfide bond with self-healing function is successfully introduced into the polyurethane structure. The hardness and thermal stability of self-healing coating all reach the requirements of conventional use. The self-healing ability of the coating is affected by the healing temperature, coating thickness and degree of damage.