讨论了在T型接头TOFD检测时如何建立模拟等腰三角形，以适应仪器内置的深度定位计算程序。介绍了显示深度与实际深度的修正计算方法，并通过计算显示深度测量值与计算值的误差，验证了上述计算方法的准确性。最后，通过对T型接头试块检测结果的分析，探讨了T型接头翼板未熔合、腹板未熔合及角焊缝内缺陷的评判规律。

This paper firstly discussed how to establish simulated isosceles triangle in TOFD testing of T-joint to adapt to the default calculation program of depth location. Then,we introduced the modified calculation method between the measured depth and the actual depth, and verified the correctness of the above calculation method by calculating the error between the measured depth and the calculated value. Lastly, the rules of evaluating the defects, such as incomplete fusion in flange slab and web as well as defects in fillet weld on the T-joint were discussed through the analysis of the test results of T-joint.