Hydrogen doping in natural gas pipelines is one of the means to realize large-scale, long-distance and low-cost hydrogen transportation, but hydrogen doping in natural gas pipelines has brought about non-negligible impacts on pipeline operating conditions, safety and maintenance, etc., and has certain potential safety hazards. To this end, the technical research and engineering application of hydrogen doping in natural gas pipelines at home and abroad are discussed, and the main factors affecting the safe transportation of hydrogen doping in natural gas pipelines are discussed, i.e., physical changes of natural gas caused by hydrogen doping, hydrogen failure, and uneven mixing. The results show that the hydrogen doping of natural gas puts new requirements on the existing pipe materials, and relevant experiments need to be carried out in order to reveal the mechanism of hydrogen failure, and whether gas aggregation occurs after the shutdown of hydrogen-doped natural gas pipelines is closely related to whether hydrogen failure occurs in the pipelines or not. The above results clarify the risks of hydrogen-doped transportation, which can provide a reference for the promotion of large-scale hydrogen-doped mixing and transmission projects and practical operation.