Abstract: With the development and improvement of TOFD technology, the defect location and quantitative evaluation by TOFD technology has received more and more attention, thus expanding the scope of its application. In a comprehensive inspection of pressure equipment, it is often difficult to perform macro inspection by opening the tank because of the conditions and environment factors. In this paper, attempts were made to use the TOFD technology to inspect the austenitic stainless steel thin-walled propellant tank wall and it′s near surface defects through the contrast experiment, and the comprehensive inspection of pressure equipment might provide a new approach for the overall inspection of the tank.