Abstract: This paper introduces the influence of phased array probe wedge wear on the test results.The phased array sector scanning was used to detect the root incomplete welding defect, the lack of fusion in grooves and the porosity defect. The image of the three defect detection results was compared by using the intact wedge and the worn wedge to see the wedge wear effect the location of the detection and sensitivity of the detection,which in turn affects the accuracy of the test results. It is concluded that the wedge wear state must be monitored regularly to ensure the reliability of the test results and to ensure the quality of the project or product.