Against　the　backdrop　of　global　warming,　countries　around　the　world　have　taken　action　under　the　call　of　the　United　Nations　to　reform　and　innovate　various　industries　with　the　primary　goal　of　achieving　carbon　neutrality.　China　proposes　to　achieve　carbon　peak　by　2030　and　carbon　neutrality　by　2060.　From　the　perspective　of　wastewater　treatment　plants,　carbon　neutrality　can　be　achieved　by　increasing　the　organic　matter　in　sludge.　In　this　paper,　four　methods　for　increasing　sludge　organic　matter　are　discussed,　such　as　the　improvement　of　rainwater　and　sewage　combined　flow　systems,　front-end　screening　chemical　oxygen　demand　(COD),　A/B　method　–　A　section　COD　concentration,　and　anaerobic　co-digestion.　The　basic　principles,　application,　and　effects　of　these　methods　are　compared　to　give　some　strategies　for　increasing　the　energy　recovery　from　sewage　sludge.　©　2022　SPIE.