Abstract: Due to special structure and weld form of the inserted nozzle fillet weld, the difficulty of conventional A-mode ultrasonic testing and the complexity of the process are increased. In this paper, several typical defects of fillet weld of inserting nozzle for pressure equipment are discussed. The testing process is simulated by CIVA software. At the same time, the simulation test block is tested by Israel ISONIC 2009 phased array equipment, and the results are compared with those of CIVA simulation. The results show that the ultrasonic phased array inspection technology for the fillet weld of the plug-in nozzle has a good detection effect, which verifies the effectiveness of the technology and provides relevant experience for the popularization and application of the phased array inspection technology in the fillet weld of the plug-in nozzle.