Abstract: During the manufacture and use of pressure-bearing equipment, defects such as internal delamination, surface cracks, hydrogen-induced cracking, hydrogen bulging, internal pit corrosion, composite plates, and unbonding layers are prone to occur in the base material. In this paper, the phased array CIVA simulation is carried out for three typical defects. The inspection process of the base metal part is mainly studied, and the on-site inspection and verification are carried out. The simulation results are compared with the on-site inspection, and the features of various defect maps are summarized. The results show that the phased array inspection technology has a high detection rate for the defect of the base material of the pressure equipment, and can realize the detection of the defects of the base material under the conditions of running, thus helping the chemical companies to save costs and provide convenience.