Abstract: In order to reduce the operating complexity of fault diagnosis and improve the defecting efficiency of defect detection in armored equipments, the infrared thermal wave technology is introduced to armored equipments of PLA, which has been used widely in equipment maintenance in other countries. Firstly, this paper briefly depicted the basic principles and characteristics of infrared thermal wave. Then, two main factors including signal to noise ratio (SNR) and thermal excitation influencing the detection results were analyzed in detail. Finally, the experiments for fault diagnosis and defect detection were carried out. Experimental results show the engine power insufficiency can be positioned accurately without disassemble and the armored plate crack can be detected fast within 3.5s by means of this method.