Foldable cooling and heating fan

The utility model discloses a foldable cooling and heating fan which comprises a base, a reserved groove is formed in the top of the base, a polish rod is fixedly connected to an inner cavity of the reserved groove, a movable block is movably installed on the outer surface of the polish rod, a bolt is fixedly installed on the top of the movable block, and an adjusting cylinder is connected to the outer surface of the bolt in a threaded mode. The adjusting cylinder is rotated to drive the annular clamping block to move downwards, at the moment, the annular clamping block penetrates through the inner cavity of the movable block and is clamped in the inner cavity of the annular clamping groove, fixing is completed, when folding is needed, the adjusting cylinder is rotated in the opposite direction to drive the annular clamping block to move upwards, the annular clamping block leaves the inner cavity of the annular clamping groove, limiting is relieved, and folding is completed. Then the adjusting cylinder is pre