The invention discloses an air-conditioning heat exchanger which comprises an outer pipe and an inner pipe, wherein the outer pipe is a straight pipe, the inner pipe is a spiral pipe, and the outer pipe and the inner pipe are mutually sleeved. The inner wall of the outer pipe and the outer spiral wall of the inner pipe are enveloped to form a spiral pipeline, a refrigerant enters through an inlet of the spiral pipeline and flows across the spiral pipeline, a refrigerating intermediate medium relatively flows in the inner pipe, the refrigerant exchanges heat with the intermediate medium through the wall of the inner spiral pipe, and the thread pitch of the inner spiral pipe is designed as gradual change according to the change situation of volume and pressure drop caused by the phase change of the refrigerant in the heat exchange process. Through the gradual change design for the thread pitch of the inner spiral pipe of the heat exchanger, a refrigerant channel can be adapted to the volume and pressure change of the refrigerant due to heat exchange, the stable pressure and the flow velocity of the refrigerant in the heat exchanger can be ensured, and the efficiency of the heat exchanger can be guaranteed; meanwhile, pressure loss in the heat exchange process is reduced, and the working load of a compressor is reduced; in addition, the total way resistance of the refrigerant is simultaneously reduced, and the delivery power of the refrigerant is reduced.