Spiral fin type heat exchanger utilizing coaxial reversal

The utility model relates to a spiral fin heat exchanger utilizing coaxial reversal, which comprises a heat pump unit, a driving device and an underground heat exchanger embedded in a rock-soil body, and the underground heat exchanger is connected with the heat pump unit to form a closed loop; the heat pump unit comprises a compressor, a condenser and an expansion valve; the driving device can drive the inner pipes to rotate, the inner pipes are further provided with coaxial reversing devices, the rotating directions of the upper inner pipe and the lower inner pipe can be changed, and reverse rotation between the adjacent inner pipes is achieved. The underground heat exchanger comprises an outer pipe, a backfill material, a circulating working medium and an inner pipe fixing device; working media in the outer wall space of the inner pipe can enter the heat pump unit through the water pipe I inside the inner pipe. The driving device is arranged on the upper portion of the inner pipe, the bevel gear is addition