Supporting and releasing mechanism and supporting and releasing device

The embodiment of the utility model discloses a supporting and releasing mechanism and a supporting and releasing device.The supporting and releasing mechanism comprises a mounting base and at least one positioning assembly, each positioning assembly comprises a plurality of positioning parts, and the multiple positioning parts of each positioning assembly are arranged in parallel and surround a central axis; and each positioning piece is movably arranged on the mounting seat along the connecting line direction of the corresponding central axis. Each set of positioning assembly adopted by the embodiment of the utility model can act on one tire, and the multiple positioning pieces of each set of positioning assembly are arranged in a surrounding and parallel mode with the central axis as the axis, so that all the positioning pieces can make contact with the inner ring of the tire when being controlled to move in the corresponding radial direction, force is applied to the tire in all directions when the tire is