The design parameter combination of OD 1 422 mm, transportation pressure 12 MPa and steel grade X80 is adopted in China–Russian Eastern Gas Pipeline for the first time, and automatic welding is fully carried out for the first time. In order to improve the welding efficiency of automatic welding and ensure the welding quality, this paper improved and upgraded design methods and technologies from the aspects of pipeline route selection, laying, material and welding. And a series of technological researches were carried out mainly on pipeline routing, pipeline turning, pipeline crossing obstacles, technological condition of line pipes, welding groove with unequal wall thickness and pipeline reliability check. And the following research results were obtained. First, according to the route selection principles, the route shall be kept smooth and straight as much as possible and the slope shall be controlled below 12°. Second, in the design of pipeline turning, wide-angle elastic laying shall be used to replace cold and hot bends as much as possible within the allowable space. Third, in crossing a highway, a new type of slab culvert is preferentially adopted to replace the traditional casing. Fourth, speaking of pipe materials, it is necessary to strengthen parameter control, e.g. out of roundness. Fifth, as for pipeline welding, a new type of inner conical welding groove with unequal wall thicknesses is adopted. Sixth, to ensure the overall pipeline safety, route reliability shall be evaluated. In conclusion, above mentioned design improvement measures effectively improve the construction efficiency and seam quality of automatic welding, so the reliability of pipeline section can reach the target value stipulated in the regulation. Their application to the automatic welding of the China–Russian Eastern Gas Pipeline is remarkable, and they can provide technical support for the full-scale implementation of automatic welding in the following projects.