In　order　to　understand　the　law　of　overflow　pollution　in　Lecong　Town,　this　paper　conducts　research　on　the　overflow　characteristics　and　pollution　control　of　the　sewage　pipe　network　and　carries　out　two　cycles　of　monitoring　on　sunny　days　and　rainy　days.　At　the　same　time,　a　detailed　plan　is　developed　to　analyze　the　Lecong　Town　sewage　pipe　network.　The　study　finds　that　the　peak　of　pollutant　concentration　during　the　rainfall　period　in　Lecong　Town　appears　in　the　initial　20mm;　after　calculating　the　amount　of　pollutants,　it　is　found　that　the　overflow　pollutants　in　the　initial　20mm　rainfall　takes　a　larger　proportion　up　to　66%　in　the　output　of　river　water.　It　can　be　seen　that　the　generation　of　sunny-day　overflow　pollution　in　Lecong　Town　is　due　to　the　backward　flow　of　river　water　into　the　pipes,　causing　domestic　sewage　unable　to　be　treated　normally.　At　the　same　time,　the　river　water　in　the　pipe　also　directly　affects　the　generation　of　rainy-day　overflow.　Improving　the　flow　of　river　water　into　pipe　network　is　the　primary　way　to　control　the　pollution　of　sewage　overflow.　Copyright　©　2018,　AIDIC　Servizi　S.r.l.