模拟了三代堆型上部导向筒顶板的实际形状，结合实际焊缝熔深的不同情况，制作出相应的对比试块，并研究出了一套可行的基准灵敏度评定方法，解决了对我国自主设计的三代先进压水堆核电站堆型上部导向筒顶板进行超声检测的难题，可供同行参考。

Through simulating the actual shape of the top plate of the upper guide tube of the third generation reactor and considering the actual weld penetration, a reference test block was designed and a set of feasible sensitivity evaluation methods were developed, which solved the problems in the ultrasonic testing of the top plate of the upper guide tube of the third generation advanced pressurized water reactor nuclear power plant independently designed by China. What described in the paper may provide reference for peers.