The utility model relates to an air-water back flushing filter which solves the existing problems of the poor flushing effect single using the water to flush the filter in the reverse direction, and the poor regeneration effect of the filtering materials. The utility model is characterized in that an air distributing system(2) which connects with an air inlet pipe(1) is arranged at the lower side of the water collector(5) in the filtering pot(8). The utility model has the advantages of the good back flushing effect and the good regeneration effect of the filtering materials.