The utility model relates to an automatic air filtering device of a ceramic filter, including one or more air compressors, one or more gas storage tanks and an air cooling drying machine; the air compressor is connected with the gas storage tank through a pipeline; the gas storage tank is connected with the air cooling drying machine through the pipeline; and the air cooling drying machine is connected with a compressed air outlet through the pipeline. In the utility model, a built-in oil separation filter of an air compressor carries out a primary filteration, the gas storage tank performs condensation of oil and water under a natural temperature difference and a secondary separation from the air, the cooling drying machine performs the condensation and filteration for the third time, accordingly, the cooling temperature achieves approximately zero DEG C, oil and water are fully separated from the air and automatically drained by the cooling drying machine drainage device and the water and oil content is controlled under 0.5% after treatment.