隧道三岔口施工是目前长大隧道施工关键之一，施工方法也多种多样。为使三岔口施工方法的选择与技术的应用更趋安全、经济与合理，结合新建兰渝铁路木寨岭、同寨和桃树坪等隧道三岔口施工实践，对其所采用的施工技术和工艺特点进行分类说明，并通过实践应用，对关键技术及相关指标进行对比分析。认为： 长大隧道三岔口施工技术应因地制宜，并结合安全风险、地质条件及工程特点等因素综合确定，同时需注意施工过程中的工序转换、施工组织及关键技术的控制。

The construction of junction sections of long tunnels is the key points of the tunnel construction. There are many junction section construction methods. The features of the junction section construction methods adopted in the construction of Muzhailing tunnel, Tongzhai tunnel and Taoshuping tunnel on LanzhouChongqing railway are presented, compared and analyzed, so as to achieve safe, economic and rational junction section construction methods. It is concluded that the risks, geological conditions and project features should be considered in the selection of the junction section construction methods and that attention should be paid to the construction procedure transition, construction organization and key technologies.