Abstract: The application of coating technology is more and more widely used in aero engine. A nondestructive testing method based on infrared thermal wave imaging technology is introduced. The method uses laser scanning as the source of heat excitation, the infrared image sequence is collected and analyzed by infrared thermal imager, and the test results are obtained. It is applied to the interior of the aero engine coating. In the defect detection, the results show that it can detect the layer defects of the coating quickly and has certain detection ability for the smaller defects. Furthermore, the metallographic technique is used to dissect the specimen and verify the result of the nondestructive testing of the laser scanning thermal wave. It shows that the technology can reliably detect the defects of the aero engine coating.