The influence of environmental temperature rise and lining deterioration on tunnel service performance in cold regions is investigated. Concrete mechanical parameter degradation is first examined through freeze-thaw cycle tests. A thermal coupling numerical model between lining and surrounding rock is then established to analyze freeze-thaw circle evolution characteristics and structural internal force time-variation patterns. Experimental results reveal that tunnel lining surfaces experience approximately 18 equivalent annual freeze-thaw cycles without insulation layers. After 50 service years, lining elastic modulus and axial compressive strength are reduced by 89% and 97% respectively. Ambient temperature elevation is found to intensify surrounding rock melting range expansion, induce lining structure settlement, and accelerate structural failure progression, resulting in 3-6 years shorter service life compared with non-heated conditions. When a 5cm-thick insulation layer is installed, annual equivalent freeze-thaw cycles at lining surfaces are decreased to 0.75 times. Elastic modulus and axial compressive strength reductions after 50 years are limited to 8% and 13% respectively. Mechanical state improvements at haunch and side wall regions are observed following insulation layer installation, while safety factors at vault, arch foot, and inverted arch sections show progressive decline. The arch foot section is identified to become bearing-inadequate after approximately 42 service years.