An automatic sewage treatment system, comprising an automatic sewage treatment device and a biological carrier, wherein the automatic sewage treatment device comprises a housing ; one side of the housing is provided with a sewage inlet , and the other side thereof is provided with a sewage outlet ; the sewage inlet is installed on one side of a No. 1 biochemical pool ; one side of the No. 1 biochemical pool is connected to a No. 2 biochemical pool through a connecting pipe ; the other side of the No. 2 biochemical pool is connected to a No. 3 biochemical pool through the connecting pipe ; the other side of the No. 3 biochemical pool is connected to a No. 1 filter mechanism through the connecting pipe ; the other side of the No. 1 filter mechanism is connected to a No. 2 filter mechanism through the connecting pipe ; the housing wall of one side of the No. 2 filter mechanism is provided with the sewage outlet ; the bottom of the No. 2 filter mechanism , the No. 1 filter mechanism , the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are equipped with microporous aeration pipes; the microporous aeration pipes are connected to an aerator through gas pipelines; the aerator is installed on the top of the housing ; one side of the aerator is connected with a distribution box ; the upper part of the No. 2 filter mechanism , the No. 1 filter mechanism , the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are provided with a manhole cover ; one side of the manhole cover is provided with a gas valve , and the other side thereof is provided with a detection hole ; the biological carrier includes a mobile microorganism carrier and a fixed microorganism carrier ; the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are provided with the mobile microorganism carrier ; characterized in that the No. 2 filter mechanism and the No. 1 filter mechanism are equipped with a porous partition ; the upper part of the porous partition is provided with the mobile microorganism carrier , and the lower part thereof is provided with the fixed microorganism carrier ; the porous partition is drilled with a plurality of through holes. the bottom of the No. 2 filter mechanism , the No. 1 filter mechanism , the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are equipped with microporous aeration pipes; the microporous aeration pipes are connected to an aerator through gas pipelines; the aerator is installed on the top of the housing ; one side of the aerator is connected with a distribution box ; the upper part of the No. 2 filter mechanism , the No. 1 filter mechanism , the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are provided with a manhole cover ; one side of the manhole cover is provided with a gas valve , and the other side thereof is provided with a detection hole ; the biological carrier includes a mobile microorganism carrier and a fixed microorganism carrier ; the No. 3 biochemical pool , the No. 2 biochemical pool , and the No. 1 biochemical pool are provided with the mobile microorganism carrier ; characterized in that the No. 2 filter mechanism and the No. 1 filter mechanism are equipped with a porous partition ; the upper part of the porous partition is provided with the mobile microorganism carrier , and the lower part thereof is provided with the fixed microorganism carrier ; the porous partition is drilled with a plurality of through holes. <EOS>