An energy-saving variable air multi-channel air conditioning unit is characterized by comprising a machine case; a fresh air inlet is formed in the left side of the upper end of the machine case; an air supply outlet is formed in the right side of the upper end of the machine case; an air return inlet is formed in the left side of the machine case; a plurality of surface air coolers are arranged in the middle of the machine case. One end of each surface air cooler is provided with filters, and inbuilt air valves are arranged on the two sides of each surface air cooler. One side of each surface air cooler is provided with a cleaning device. The tail ends of all the surface air coolers are connected through a water inlet/outlet pipe and extend to the outer side of the machine case. The energy-saving variable air multi-channel air conditioning unit has the advantages energy consumption is low, resources are saved, the time for air passing through the surface air coolers is shortened, the flow of the air is reduced, the dust, accumulated on the surfaces of the surface air coolers, in the air is reduced, the heat exchange efficiency of the surface air coolers is improved, and service life is prolonged.