Sewage treatment method and system combining biological contact oxidation with MBR (Membrane Bioreactor) and microfiltration membrane filtration

The invention discloses a sewage treatment method and system combining biological contact oxidation with MBR (membrane bioreactor) and microfiltration membrane filtration, and the method comprises the following steps: carrying out primary treatment on sewage by using a biological contact oxidation device to remove part of sludge and harmful substances in the sewage; performing secondary treatment by using an MBR (Membrane Biological Reactor) and a separating and filtering device to further remove part of sludge and harmful substances in the wastewater; carrying out third treatment by using a micro-filtration membrane separating and filtering device to further remove residual sludge and harmful substances in the wastewater so as to obtain primary clear water; the primary clear water reaches the standard through disinfection treatment; and respectively pumping part of standard clear water back to the cleaning biological contact oxidation device, the MBR membrane biological reaction and separation filtering devi