Abstract: In order to inspect some inaccessible areas for the infrared NDT, the author provides with a new technique, using specular reflection to expand the reachable area in practical work. This paper gives a brief introduction on the test principle and system. Different test specimens are designed and manufactured with artificial defects. Series of tests are carried out on these specimens by infrared NDT with or without specular reflection. The results are compared and analyzed after the tests. Some determined influencing factors of the test sensitivity are given and the related influencing factors are discussed. More details and suggestions are given in the end to promote the test and technique.