Abstract: With capillary suction time (CST) and centrifugal sedimentation ratio (SV) as sludge dewatering performance index, potassium persulfate, ultrasonic microwave combination technology(UMCT), pyrophyllite single factor and the effect of three factors coupling improved sludge dewatering properties.According to the results of single factor experiment, the best range of values, the response surface methodology (RSM) and analysis of variance were used to obtain the best value of the coupling of the three factors.Under the optimal conditions of sludge dehydration, the dosage of potassium persulfate was 0.15 g/g, the UMCT treatment time was 12 s, the dosage of pyrophyllite was 0.35 g/g, SV and CST were 32.5% and 38.4 s, respectively, which were basically consistent with the predicted values.In addition, SEM, particle size analysis and thermogravimetric analysis(TG-DTG) were used to further verify the results, which improved the reliability of the conclusions.