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管道内壁受冲刷和腐蚀而减薄，常常发生泄漏事故，不仅造成经济上的巨大损失，而且造成人身伤害，污染环境，根据我国石油天然气管道安全规程的规定，管道应进行定期全面检测，检测周期为5年，文章介绍了天然气管道的内部漏磁检测原理和技术性能，指出管内漏磁检测是替代管道静压试验的一种有效方法，它对于管道安全运行评定具有十分重要的意义，使用天然气管道的内部漏磁检测方法，管道检测前的准备工作至关重要，应确保管内无阻塞，管内有效直径达到内径的95%以上，并应精心设计管道捕获器，以确保管内漏磁检测的顺利进行，最后，还介绍了国外管内漏磁检测的发展趋势。

Internal Magnetic Flux Leakage Detection Technique of Natural Gas Pipeline

Because of the inside pipe wall' s being thinned owing to washout and corrosion, leaking accident often happened, which caused mot only a tremendous economic loss but also a personal injury and environmental pollution. According to the rules in the oil and gas pipeline safety regulations issued by China, the pipelines should be detected regularly and all-sidedly with a detection period of five years. In the paper, through introducing the principle and technological properties of internal magnetic flux leakage detection of natural gas pipeline, it is pointed out that the internal magnetic flux leakage detection is an effective method to replace the pipeline hydrostatic testing and it is of great significance for evaluating pipeline safety operation. In order to use the internal magnetic flux leakage detection method for natural gas pipeline, the preparations are very important before detecting. It is necessary to guarantee the pipeline not to be obstructed, guarantee that the effective pipeline insi de diameter accounts for more than 95 percent of the pipline inside diameter,and guarantee the pipeline catcher to be designed carefully, so as to make the internal magnetic flux leakage detection be smoothly conducted. Finally the developing trend of foreign internal magnetic flux leakage detection is also introduced in the paper.