The utility model discloses a take sewage treatment system of mixed liquid recycle device, link to each other, locate the aeration head of oxygen bottom of the pool portion through the gas supply line including anaerobism pond, good oxygen pond, air feeder with air feeder, still including connecting the anaerobism pond oxygen pond of becoming reconciled, mixed liquid recycle in will good oxygen pond to the backflow pipeline in anaerobism pond, its characterized in that: still include an admission line, admission line one end connect air feeder, the other end sets up inside backflow pipeline, and the gas outlet is upwards the same with the mixed liquid recycle direction. Take sewage treatment system of mixed liquid recycle device, the beneficial effect who has is: make good use of unnecessary gas behind the aeration of oxygen pond, will mix liquid and pass through the back flow and flow back in the anaerobism pond, reduced the backwash pump, practiced thrift the energy consumption, the cost is reduced.