In　railway　tunnels　located　in　cold　regions,　frost　damage　is　constantly　emerging,　which　seriously　affects　the　safety　of　railway　tunnel　operations.　While　having　general　thermal　insulation　effects,　thermal　insulation　measures　developed　in　previous　studies　have　not　solved　the　problem　of　frost　damage　in　operational　railway　tunnels.　To　fill　this　gap,　this　paper　puts　forward　a　new　composite　thermal　insulation　lining.　Firstly,　through　numerical　simulation,　this　new　composite　thermal　insulation　lining　was　verified　to　have　better　mechanical　properties　and　insulation　effects　than　general　steel　plate　thermal　insulation　lining.　The　fast　construction　method　of　thermal　insulation　lining　is　proposed　to　have　excellent　construction　efficiency　and　great　economic　and　social　benefits.　According　to　field　monitoring　data,　the　outer　surface　temperature　of　the　lining　reached　about　5　degrees　C　in　winter　after　the　new　composite　thermal　insulation　lining　was　added,　which　fundamentally　inhibited　the　formation　of　ice　and　effectively　avoided　frost　damage.　At　the　coldest　moment　in　time,　the　temperature　of　the　secondary　lining　was　about　9　degrees　C　higher　than　without　thermal　insulation　lining.　In　summary,　compared　with　existing　anti-freeze　technology,　the　new　composite　thermal　insulation　lining　has　better　thermal　insulation　capacity,　can　be　constructed　faster,　and　offers　clear　economic　benefits.