Thermal insulation longitudinal blind pipe used in cold region highway tunnel

The invention discloses a thermal insulation longitudinal blind pipe used in a cold region highway tunnel, and relates to the technical field of longitudinal blind pipes. The thermal insulation longitudinal blind pipe used in the cold region highway tunnel comprises an inner sleeve, a hard polyurethane thermal insulation layer and a filter assembly, wherein the inner wall of the inner sleeve is provided with a hydrophobic coating, the outer side of the inner sleeve is provided with an outer sleeve, the hard polyurethane thermal insulation layer is filled between the outer sleeve and the innersleeve, and one side of the outer sleeve is provided with a water inlet hole; and the filtering assembly is installed on the inner side of the water inlet hole, a geotextile layer is fixed on the outer side of the water inlet hole, a flow channel is arranged on the inner side of the inner sleeve, a steel wire ring is wound on the outer wall of the inner sleeve, and the fixing assembly is installedon the outer side of the