Abstract: Radiographic testing is an important means to ensure the quality of welds during the construction of nuclear power plants, but it has certain limitations, including low detection rate of area defects, radiation safety risks, low inspection efficiency, and high inspection costs. This paper developed the Phased Array Ultrasonic Testing (PAUT) procedure of fine-grainted ferritic steel pipe welds with more than 12 mm thickness. Also the defect detection rate, quantitative deviation and location error of PAUT were analyzed by constrast with that of RT. The results show that phased array ultrasonic testing can reach or even surpass the detection ability of traditional radiographic testing, and has broad application prospects.