Underground heat exchange combined pipe of geothermal well

The invention belongs to the technical field of geothermal energy utilization, and particularly relates to a geothermal well underground heat exchange combined pipe which comprises a heat transfer layer arranged on the inner wall of a vertical well, a turbulent flow anti-blocking structure arranged at the bottom of the inner side of the heat transfer layer, a heat insulation sleeve in shaft connection with the top face of the turbulent flow anti-blocking structure, and a heat flow gap formed between the heat insulation sleeve and the heat transfer layer. The top end of the heat flow gap fixedly communicates with one end of the cold water pipe. The inner side of the heat insulation sleeve is sleeved with a sectional communicating pipe structure. The bottom end of the sectional communicating pipe structure is fixedly communicated with the turbulent flow anti-blocking structure through a bottom connector, a sealing connecting structure is arranged between the bottom connector and the turbulent flow anti-blocking