Method for welding pipelines in tunnel

The invention relates to a method for welding pipelines in a tunnel, which is characterized by comprising the following steps of: a, distributing the pipelines, namely transporting the pipelines to be welded into the tunnel by using a tunnel pipeline transporting vehicle to distribute the pipelines; b, aligning: adjusting postures of the secondary pipe and the primary pipe from the outside of the pipeline by using a tunnel pipe conveying vehicle for aligning, and simultaneously aligning from the inside of the pipeline by using an internal welding machine; c, internal welding: after the opening aligning step is completed, welding an interface in the pipeline by using an internal welding machine; and d, filling and welding: filling and welding the interface from the outside of the pipeline. According to the method for welding the pipeline in the tunnel, the automation degree of welding construction of the pipeline in the tunnel is improved, the labor intensity of people is reduced, and a project can be rapidly