A type of selfrepairing lubricant containing Sn and Zn powder additives and suitable for steelsteel tribopair is developed. Its repairing and tribological properties are reviewed on a rebuilding model MS800 tester. The tooth contact stress of gear transmission is calculated with ANSYS. The findings showed that repairing coatings can be formed on steel surface because of the SnZn selfrepairing lubricant, which has good antifriction and antiwear properties under different loads. Simulation results indicate that tooth contact stress is reduced by 16.7% after repairing with the lubricant.