由于聚乙烯材料超声波衰减系数大，以及电熔接头中金属丝信号对检测的干扰，使得传统的超声检测方法并不能有效地检出聚乙烯电熔接头中的各类缺陷。采用超声相控阵动态聚焦，结合B扫查成像技术，可以解决上述难题。将超声检测图像与接头实剖图进行对比，证明该方法能可靠地检出聚乙烯电熔接头中的各类缺陷,并在聚乙烯管道安装工程的实践检测中得到进一步验证。

It is difficultly for conventional ultrasonic technique to find the discontinuities of electro-fusion joint in Polyethylene pipe due to the heavy ultrasonic attenuation and disturbance by wire in the joint. The above problems could be overcome by phased array ultrasonic focusing technique as well as B-scan real image technology. The technique was proved having ability to find the discontinuities of electro-fusion joint in Polyethylene pipe through contrast between the Ultrasonic images and dissected samples, and further proved by the on-site testing practice in Polyethylene pipe installation engineering.