When　sludge　produced　by　sewage　treatment　plants　is　improperly　treated,　it　causes　secondary　pollution　to　the　environment.　Direct　treatment　is　time-consuming,　labor-intensive,　and　consumes　enormous　resources;　therefore,　pretreatment　is　required　before　sludge　discharge.　Sludge　treatment　with　ultrasonic　coordinated　micro-bubbles　revealed　that　at　30　s　of　ultrasonic　treatment　time,　450　W　of　power,　and　5　min　of　micro-bubble　treatment　time,　the　volatile　fatty　acids　content　was　the　highest　at　204.64　mg/L.　The　sludge　cracking　was　analyzed　by　the　polysaccharide　content　in　extracellular　polymers　substances.　The　total　polysaccharide　content　was　the　highest　(52.75　mg/L)　when　ultrasonic　treatment　was　performed　for　30　s.　The　types　and　distribution　of　dissolved　organic　matter　in　the　supernatant　were　analyzed　by　three-dimensional　fluorescence　spectroscopy.　Based　on　volatile　fatty　acids,　the　order　of　influence　among　the　three　factors　is　bubble　treatment　time　＞　ultrasonic　time　＞　ultrasonic　power,　as　shown　by　the　response　surface　method　experiment.　After　synergistic　treatment　with　ultrasonic　and　micro-bubbles,　the　Fourier　transform　infrared　spectroscopy　showed　a　change　in　the　chemical　properties　of　the　sludge,　thus　affecting　the　dewatering　performance.　Under　the　combined　action　of　the　two　treatments,　scanning　electron　microscopy　showed　that　the　sludge　particles　became　smaller　with　a　loose　structure,　which　was　beneficial　to　improving　the　dewatering　characteristics.　These　results　provide　a　basis　for　the　industrial　application　of　ultrasonic　coordinated　micro-bubbles　sludge　treatment.