The utility model relates to a heat insulation coupling, and belongs to the heavy oil thermal recovery underground tool field. The heat insulation coupling comprises a coupling body, positioning sleeves and a coupling outer tube, wherein tapered internal threads are arranged at two ends of the coupling body, the coupling outer tube sleeves the coupling body, the positioning sleeves are placed between the coupling body and the coupling outer tube, the positioning sleeves are arranged at two ends of the coupling body, a closed annual space is formed among the outer surface of the coupling body, the inner surface of the coupling outer tube and the inner side faces of the positioning sleeves, the closed annual space is filled with a thermal insulation layer, oxygen absorbing agents are placed on the outer surface of the thermal insulation layer, and vacuum pumping pinholes are formed in the coupling outer tube. The heat insulation coupling reduces thermal loss of the heat insulation coupling from three aspects of thermal convection, thermal radiation and thermal conduction, and is good in heat insulation performance and simple in structure.