Abstract: The manufacturing quality of tension clamps for transmission lines is crucial for the safe and stable operation of overhead transmission lines. With the rapid development of the power grid, the performance requirements for tension clamps of transmission lines are constantly increasing. A method using phased array ultrasonic testing technology to supervise the manufacturing quality of angle welds in tension clamps was proposed based on the defect characteristics of angle welds. Acoustic field and defect response simulation were conducted using CIVA software, and phased array ultrasonic testing was used to detect typical angle weld defects in tension clamps, and the detection results were verified and compared. The results indicated that phased array ultrasonic testing technology had a strong ability to detect defects in this type of fillet weld and was an effective means of quality supervision in the manufacturing of tension clamps.