Abstract: Based on the experiments of the phased array ultrasonic testing of preset defects of nuclear power concrete, the simulation analysis of phased array measurement and the reliability verification of the model were verified by COMSOL. Furthermore, the verified simulation method was used to study the influence of different deflection angles and focusing distances of phased array arrays on ultrasonic detection, which provided a reference for the engineering design of ultrasonic phased array probes. The results showed that phased array ultrasonic testing was an effective nondestructive testing method. COMSOL multiphysics simulation software can correctly simulate the propagation of sound beams in defective concrete; The phased array used different beam deflection angles and focusing distances, which have an impact on the detection results. This conclusion provided reference for the engineering design of phased array ultrasonic probes for concrete testing.