TOFD（超声波衍射时差法）检测中声束交点的设置对检测结果的可靠性至关重要。对不同声束交点深度的衍射声场特性进行仿真分析，通过试验测试不同交点深度对扫查面盲区的影响及衍射声场的分布，并在模拟试块上进行了实测验证。结果表明，当声束交点深度为0.6T（T为工件厚度）时，衍射声场对检测区域的覆盖性更好，且扫查面盲区较小，有利于提高检测质量。该结果可为TOFD检测技术人员优化检测工艺提供参考。

Setting of the intersection of sound beams in TOFD testing is critical to the reliability of the detection results. In this paper, the characteristics of the diffracted sound field at different depths of the intersection of sound beams are simulated and analyzed. The effect of different depths of the intersection on the blind area of the scanning surface is tested through experiments, and the actual measurement is verified on the simulated test block. The results show that when the depth of the intersection point of the sound beam is 0.6T, the coverage of the diffracted sound field to the detection area is better, and the blind area of the scanning surface is smaller, which is beneficial to improve the detection quality. This result can provide a reference for TOFD technicians to optimize the detection process.