The invention discloses a thermal insulation pipe assembling machine which comprises a frame and an electric cabinet, wherein the electric cabinet is arranged in the frame; a pipe straightening mechanism, a first pipe feed mechanism, a sawing mechanism, a second pipe feed mechanism and a thermal insulation pipe clamping device are sequentially arranged on the surface of a working platform of the frame along the feed direction of a pipe; the first pipe feed mechanism is used for feeding the pipe to the thermal insulation pipe clamping device; the thermal insulation pipe clamping device is used for clamping a thermal insulation pipe; the pipe penetrates through the thermal insulation pipe by the second pipe feed mechanism; and an electric operating platform connected with the electric cabinet is also arranged on the frame and manually or automatically controls all the mechanisms on the frame. The invention can assemble the single pipe or double pipes and replace a corresponding jig and a rolling wheel according to the specifications of the pipes so that equipment can simultaneously process a plurality of pipes with various specifications; the processing efficiency is improved, and the utilization ratio of the equipment is high; the equipment operation is simple, flexible and convenient, two ways of manual control and automatic control are adopted, and thermal insulation pipe penetration can be manually operated and can be also fully automatic.