Abstract: In this paper, a sealed ring assembly is taken as the experimental research object. By monitoring the ultrasonic echo amplitude at the bonding layer, the detection resolution and penetration force are analyzed, and the quality of vacuum brazing bonding is evaluated. The optimum testing parameters of annular superalloy vacuum brazing parts are obtained and applied to actual parts testing. The test results show that ultrasonic testing can find the position of poor welding quality in time, which has certain application value.