The utility model relates to a sewage treatment device, pack including oxygen deficiency unit, good oxygen unit, mud -water?separation unit, baffle assembly and suspension, the oxygen deficiency unit good oxygen unit with the mud -water?separation unit passes through baffle assembly communicates in proper order, the last water hole of having seted up of baffle assembly, the intussuseption of good oxygen unit is equipped with the suspension is packed, inside water distribution device, ordinary filler and the water collector of being equipped with of oxygen deficiency unit, good oxygen unit bottom is equipped with aerator and sewage cycle mouth, be equipped with filter equipment in the mud -water?separation unit, filter equipment pass through the pipeline with the delivery port that mud -water?separation unit upper portion was equipped with links to each other, mud -water?separation unit bottom is equipped with the mud pipe. The beneficial effects of the utility model are that: adopt intermittent type formula wastewater treatment process, increased the reflux ratio of mixed liquid, improved anti impact load's ability, reduced mud output, promoted the stability of denitrogenation efficiency.