Middle-deep layer geothermal energy collection same-well pumping-back system

The invention relates to the technical field of geothermal energy collection, in particular to a medium-deep layer geothermal energy collection same-well pumping-back system. Comprising a collecting well, a heat exchanger and a filtering and purifying unit, when filtering filler in a filtering cavity needs to be cleaned, a rotating assembly is started, a rotating ring is driven by a transmission gear to rotate on a first cleaning box, so that a threaded rod is screwed in the rotating ring, and then a mounting frame is driven by a connecting bearing to slide in a filtering box body; according to the structure, the inner diameter of the filter cavity, where impurities are not attached, on the mounting frame is matched with the inner diameter of the filter box body, the filter cavity, where the impurities are attached, on the mounting frame moves into the corresponding first cleaning box and the second cleaning box, and therefore the filter filler in the filter cavity needing to be cleaned is washed through the