Abstract: Coating damage in the construction of new pipeline, and the corrosion defect in the in-service pipeline will adversely affect the safety of pipeline. The pipeline outside detection can find coating defect in time and guide the repair and maintenance of pipeline. The paper expounded the working contents of outside detection of long distance pipeline. From the aspect of pipeline coating detection technology, the advantages and disadvantages and applicability of more mature and advanced outside detection technology were introduced, such as the standard pipe/ground voltage detection technology ( P/S) ，Pearson detection technology，pipeline current mapping technology，the direct-current voltage gradient( DCVG) method，and the close interval potential method( CIPS)．In addition, it also included the non-excavation external detection technology. The application and practical experience of outside detection technology in pipeline engineering in China were systematically summarized, and the main problems in application are analyzed. Finally, the future development trend of pipeline outside detection technology was prospected.

摘要： 新建管道施工中防腐层破损，以及在役管道腐蚀缺陷，都会对管道安全造成不利影响。管道外检测可及时发现防腐层缺陷，指导管道修复维护工作。阐述了长输管道外检测的工作内容，重点针对管道防腐层外检测技术，介绍了较为成熟、先进的外检测技术的优缺点和适用性，包括标准管-地电位测试技术、皮尔逊检测技术、多频管中电流测试技术、直流电位梯度法、密间隔电位测试技术等，此外还包括了新兴的非开挖检测技术。系统总结了外检测技术在我国管道工程的应用情况和实践经验，并分析了应用中存在的主要问题。最后，针对管道外检测技术未来发展趋势进行了展望。

关键词: 管道 外检测 防腐层 腐蚀 缺陷 干扰, Pipeline Outside Detection Coating Corrosion Defect Interference