The present invention provides a method capable of substantially reducing the sludge amount in sludge treatment. According to the method, the filler for filling the biological carrier in the sewage treatment main process is rich in a variety of trace elements for microorganism growth, the unique form of the biological carrier can form the DO changeable environment, the sludge retention time (SRT) is long, the variety is rich, the food chain is long, and the newly-generated sludge is progressively re-degraded by a variety of microorganisms so as to achieve the sludge reduction purpose. According to the present invention, the sludge generation amount of the sewage treatment process is reduced to 0.1-0.15% of the sewage amount from 0.8-1% of the sewage amount, the uncoupling agent adding is not required, no secondary pollution is generated, the variety and the quantity of the microorganisms can be easily controlled, the control is easy, the effect is significant, the application range is wide, the method can be used for treating municipal wastewater, park wastewater, industrial wastewater, domestic wastewater and other organic wastewater, the operating is stable, the changes of the hydropower and the water quality can be bore, and the adjust workload is low.