Abstract: A phase-change energy storage air duct of an automobile air conditioning system. A phase-change energy storage unit (2) is configured inside an air duct (1) of an air conditioning system. By means of phase-change heat absorption or release, residual heat in the air is absorbed, and the heat is released to air with a lower temperature, so that energy is recycled to achieve energy saving. The temperature of air entering a room or a carriage is kept stable, and thus the user experience is improved. When the air conditioning system fails, the phase-change energy storage unit (2) can still utilize stored cooling capacity or heat to cool down or heat up air in the air duct, so that a supply of air can be kept stable for a period of time, and thus the user experience is improved. The present application also relates to an automobile air conditioning system.