This　paper　has　designed　a　novel　off-wall　insulation　liner,　aiming　to　prevent　severe　frost　damages　for　the　high-speed　railway　tunnel　in　cold　regions.　In　terms　of　composition,　the　double-layer　steel　corrugated　plates　of　the　liner　not　only　prevent　the　block　falling　and　water　intrusion　of　cold-region　tunnels　but　prolong　the　durability　and　effectiveness　of　thermal　insulation　materials.　Besides,　the　quick-construction　technology　for　the　off-wall　insulation　liner　was　derived　in　the　present　study,　and　it　exhibits　excellent　construction　efficiency,　great　economic　and　social　benefits　in　the　highspeed　railway　tunnel.　Concerning　the　insulation　capacity,　the　double　insulation　layers　(polyurethane　foam　and　air)　perform　the　dramatical　coldness-blocking　effect,　the　freezing　line　moves　forward　from　0.48m-deep　surrounding　rock　to　the　lining　surface.　The　four-year　field　test　has　proved　the　effectiveness　and　insulation　capacity　of　the　off-wall　tunnel,　the　severe　frost　damages　in　the　Wufengshan　tunnel　were　successfully　eliminated.　Compared　with　existing　coldproof　measures,　the　off-wall　insulation　liner　in　this　paper　exhibits　excellent　insulation　capacity,　high　construction　efficiency,　and　excellent　economic　benefits,　it　could　be　applied　in　the　high-speed　railway　tunnels　with　high-altitude　or　extremely　low　temperatures.