针对复合材料制件里常见的变厚度层压板结构，提出了一种基于多电子闸门的脉冲回波法超声C扫成像技术。其基本原理是在变厚度层压板最厚区域的上下表面回波之间设置多个首尾相连的闸门分别采集信号成像，形成若干副C扫图像，通过分析这些图像的组合得到试件各个区域的内部缺陷信息，从而解决脉冲回波法检测中变厚度层压板底波位置变动的问题。通过对含人工缺陷变厚度层压板的超声检测，验证了上述技术的可行性。

This paper intriduces a pulse echo ultrasonic C scan imaging technology based on multi-electron gate aiming to test variable thickness laminates structures which are extensively used in composite parts. The basic principle is to set a plurality of end to end gates on the echo of surface and bottom for the thickest area of variable thickness laminate to collect the signal and form several pairs of C scan images, which can obtain the internal defects information of different regions by analyzing these images. This technology can solve the problem of bottom wave shifting in pulse echo method. The feasibility of this technology is well proved by using ultrasonic C to detect the variable thickness laminates with artificial defects.