Abstract: The dual pipe laying for Lanzhou-Chengdu Crude Oil Pipeline and the tunnel crossing section of Zhongwei-Guiyang Linkline in Kang County is quite difficult. The traditional pipeline installation machines and equipments can notbe used in tunnels. For the limited space for dual pipe laying in tunnels, self-powered gantry, mechanical pipe carrier andtunnel welding car were designed and the welding requirements for two kinds of tubes were also proposed in this paper. Inaddition, the installation procedure and operation points of preparation, piping, tubing, assembly and welding in the streamlineoperation of tunnel pipeline installation. Compared with traditional tunnel rail installation method, the method proposed in thispaper is more convenient, efficient and economical.