Linzhi-Ranwu railway project is located in Bangong Co-Nujiang junction zone. The geology characteristic、activity and stress-strain appearance have significant influences and restrictions on the project. Bases on field investigation of geological formation and structure, this paper try to conclude engineering effects through thorough analysis oriented with stress-strain appearance and junction zone formation and structure.the results are as fllows: Bangong Co-Nujiang junction zone is at steady state overall but the eastern fault has shown high activity; The whole stress level in junction zone is quite high and caused NW-NWW compression deformation; The cover sediments and crystalline basement flow upon the low-velocity zone and the soft lower crust, the junction zone and Gangdese Nyainqentanglha block dive toward northeast; The stress between the eastern and western block is barely equal as the junction zone is compressed tightly and can only dissipate few energy from west; The key engineering geological problems are different in separate regions. Junction zone has shown high compression with dextral shearing, the western block-Gangdese Nyainqentanglha reflects high ground pressure and rockmass effects, the eastern block Southern-Qiangtang presents as deformation in soft rock tunnels.