Based on mathematical simulation method,an optimization scheme of aeration system was proposed to save energy,which reduced the number of running aeration brush from 5 to 4 in the middle ditch under the normal operation condition.When the increasing degree of inflow was over 25%or the substrate concentration above 50%,the number of running aeration brush would be increased to 5.When the inflow were lower than normal condition,the number would be decreased to 3.With implementing this scheme for two months,the water quality of effluent could always meet the first class of B standard.