Censtar double-layer pipeline consists of a main pipeline and an outer pipeline, both of which are manufactured using the same process. The inner main pipeline and the outer pipeline, connected with a dedicated electric hot-melt plastic pipe fitting, form an interlayer space along the entire pipeline, and the space is closed with dedicated electric hot-melt plastic pipe fittings at both ends of the pipeline. The leakage of the whole system can be monitored using a leakage monitor. The double-layer oil pipeline can not only transport liquid fuels and monitor the leakage of the entire conveying system online, but also provide safer measures to prevent the environment from being contaminated by fuels.