The status of the difficult repairing construction of the yellowish topcoat was described,and the reason of repairing spray color difference and polishing discoloration was analyzed.After optimization and adjustment,adding different manufacturers of leveling aids,conducting relevant test tests,the solution and verification measures were determined,it solved the problem of repairing spray color difference and polishing discoloration,improved the quality of repairing the paint surface of the yellowish topcoat and delivery progress.