Domestic sewage treatment system for offshore platforms or ships

The invention relates to a domestic sewage treatment system for offshore platforms or ships. The treatment system comprises a grid tank, a regulating tank, a first-level sedimentation tank, a micro-electrolytic tank, a contact oxidation tank, a membrane bioreactor, a second-level sedimentation tank and a sterilization device, wherein a crushing pump is arranged on one side, positioned at the upstream of the sewage, of the bottom of the grid tank; sludge discharging pipes are arranged at the bottoms of the first-level sedimentation tank, the micro-electrolytic tank, the contact oxidation tank, the membrane bioreactor and the second-level sedimentation tank; the sludge discharging pipes are connected with a sludge drying tank through sludge reflux pumps; the contact oxidation tank is divided into three compartments by clapboards, the first compartment is filled with ABS resin, polyvinyl chloride plastic is arranged in the second compartment, and polymeric sponge padding is arranged in the third compartment; a membrane component is arranged in the membrane bioreactor; microporous aeration heads are arranged at the bottoms of the contact oxidation tank and the membrane bioreactor; the microporous aeration heads are connected with an air pump through aeration pipelines. According to the treatment system, the contents of CODCr, NH3-N, and the like, in the sewage can be further reduced, so that the sewage can reach the emission standard.