A technology for reducing and recycling treatment of 
sludge of a 
sewage treatment 
plant comprises steps as follows: 
sewage is treated with an air-floatation method, pretreated 
sewage and primary 
sludge are produced, the pretreated sewage is drained after biochemical treatment, treatment by a secondary 
sedimentation tank and disinfection treatment, excess 
sludge is separated in the secondary 
sedimentation tank, the primary sludge and the excess sludge are concentrated, and concentrated sludge and a supernate are separated out; the concentrated sludge has an 
anaerobic digestion reaction, digested sludge is subjected to 
incineration or landfill treatment after 
dehydration and 
drying treatment, a filtrate is produced during 
dehydration of the digested sludge, and 
biogas is subjected to power generation and / or heat 
recovery treatment after 
dehydration and desulfurization treatment; the supernate and the filtrate are mixed for 
nitrogen and 
phosphorus removal. With the adoption of the technology, the primary 
sedimentation effect of the sewage is improved, the yield of the primary sludge is increased, the primary sludge is removed before biochemical treatment, the yield of the excess sludge is decreased from the source, the primary sludge and the excess sludge are subjected to 
anaerobic digestion treatment, the higher 
organic matter transformation rate and the higher 
biogas yield can be obtained, and the sludge can be reduced and recycled.