Introduced are main points of Shaanxi-Beijing Gas Pipeline 3 routing design (stage 1) scheme optimization and its main design achievements. Applied are synthesis techniques, experience and methods, combined are achievements and experience obtained from Shaanxi-Beijing Gas Pipeline 2 engineering design, optimized is the main pipeline routing in Shaanxi-Beijing Gas Pipeline 3 Project and preferably solved are such problem existing in Shaanxi-Beijing Gas Pipeline 3 routing design as the two pipelines laid in parallel and separated from each other. The design scheme has such characteristics as beneficial environmental protection, safe pipeline operation, low investment and operating cost, easy construction and convenient long-term operating and management. The main points of Shaanxi-Beijing Gas Pipeline 3 routing design (stage 1) scheme optimization and its main design achievements are products of elaborate survey and design and its optimization design is a successful example of large-scale gas transmission pipeline construction, which can provide useful reference for future similar pipeline engineering designs.