In order to solve the problems of low accuracy, leakiness and tedious processing existing in traditional airtight testing of dangerous goods packaging, a new type of infrared imaging airtight detector has been developed for the first time by using infrared imaging and controlling technology. The structure and working principle of the detector were introduced with the characteristics and performance indicators of its hardware and software described, while the corresponding detection method and process were established. The results showed that the device had the advantages of quick response speed, high temperature resolution and non-contact measurement, which could completely satisfy the requirement of the current testing standard, with the testing process of digital levels and safety performance improved. In the meanwhile, it could accurately locate the leak point of the packaging, which could help to improve the quality of defective products and process.