Abstract: Rationally determining the parallel laying distance of long-distance oil/gas pipelines will not only cut the land use, but also ensure the safe operation of the pipelines. Taking the Zhongwei-Guiyang Gas Pipeline and Lanzhou-Chengdu Oil Pipeline as examples, the major factors are analyzed in the safe distance for parallelly laid pipeline in heat transfer effect between hot oil transportation and gas transmission pipelines at ambiant temperature, installing space under on-line stoppling, the pipeline cracked to fail and pipeline construction/maintenance. With consideration to various influences and the geological characteristics of right-of-way along the two parallelly laid pipelines, requirements for the parallel laying distance under three conditions are confirmed. By analyzing the failure probability of oil pipeline caused by the failure of gas transmission pipeline, the feasibility is demonstrated in shouting distance parallel laying between the natural gas pipeline and crude oil pipeline.