Abstract: Metal pipelines are gradually being replaced by non-metallic materials due to issues such as corrosion and excessive weight, with PE gaining increasing prominence in the pipeline industry. However, defects including voids, cracks, and inclusions may develop during the manufacturing, transportation, installation, and operational phases of PE pipelines, potentially leading to transportation failures. Conventional NDT methods exhibit limitations and even detection challenges when they were applied to novel dielectric materials like PE. To address this challenge, this study investigated the principles of microwave reflection method for PE pipeline inspection. A computational model simulating microwave detection in PE pipelines was developed using CST Studio Suite, complemented by the implementation of a microwave based experimental test bench integrated with radio frequency (RF) circuits for empirical validation. The results demonstrated the significant potential of microwave detection technology in PE pipeline applications. The proposed RF circuit design facilitated advancements in detection system miniaturization, portability, and intelligent functionality.