With the increasing demand of the construction of long-distance pipeline, the long-distance pipeline in China has been gradually developing towards large diameter and high-grade steel. Meanwhile, an increasing proportion of pipelines are being laid in mountainous areas to meet the integrity management requirement and avoid planned urban residential areas and infrastructure facilities. After summarizing the pipeline failure incidents in recent years, it is found that the main cause is the quality of the girth weld. The pipeline welding construction in mountainous areas will face such challenges as poor geological conditions, adverse construction environment and great difficulties in construction. Therefore, it is imperative to promote full automatic welding in mountainous areas. Currently, full automatic welding with slope below 15° can be achieved, but there are no application cases for the construction of full automatic welding of mountain pipelines with large slope (greater than 15° and less than 25°). Based on the development trend of domestic long-distance pipeline automatic welding construction, this paper compares and analyzes the status quo of domestic and international technologies for automatic welding in mountainous area, and puts forward the measures that should be taken to implement full automatic welding construction for pipeline with large slope, covering the whole engineering process of pipeline development in terms of design, procurement and construction.