The invention discloses a construction method of a cold region tunnel electric heat tracing active insulation antifreezing facility, which comprises the steps of: firstly, arranging a heating cable in a secondary lining surface of a tunnel; secondly, connecting the heating cable with a temperature controller, arranging a temperature control probe connected to the temperature controller beside theheating cable; thirdly, arranging an insulation board on the heating cable; and fourthly, arranging a fireproof board on the surface of the insulation board, wherein the insulation board and the fireproof board are fixed by using steel flat and bolts. The method has a simple construction process, and materials used in the method have lower cost. The invention also discloses the cold region tunnelelectric heat tracing active insulation antifreezing facility constructed by adopting the method is environmentally-friendly, energy-saving, and convenient for construction and maintenance, and has an intelligent active insulation characteristic.