Abstract: The airtight detection of sealed devices have been focused by many enterprises, which has been seen as an important technical index of quality. Thus, the airtight detection of sealed devices is very important. In recent years, the infrared thermography detection technology has been widely valued because of its advantages of the fast response speed, the wide measuring range and the non-contact measurement. But there is no study about its application and research in gas tightness detection technology. Through theoretical analysis and experimental research, a kind of gas tightness detection method based on infrared thermography is put forward, which is on the basis of the existing air tightness detection method and the analysis of its application. Fluent software is used to simulate the temperature field of the leak. In test, through the heat analysis of the measured container with a defect, the temperature field distribution of leak is obtained. The results of the test provide the basis for leakage of judgment based on infrared thermography.