In recent years, the marine aquaculture has been undergoing a rapid development in the quantity and the scale of this industry. The wastewater from marine aquaculture inevitably causes pollution to the adjacent sea water if discharged without proper treatment. In order to meet the criteria of recycling or discharge, currently people have mainly used physical, chemical, and biological methods to remove the suspended solids (SS) and ammonia nitrogen in the wastewater, and to reduce chemical oxygen demand (COD) and biological oxygen demand (BOD). However these traditional methods have certain shortcomings in processing wastewater generated in marine aquaculture. Compared to the traditional treatment, membrane technology has the advantages such as the convenient operation and management and high efficiency, although it brings in membrane pollution during the application. In this study, we coated polysulfone ultrafiltration membrane with dopamine, and examined the properties and the functional performance of the dopamine composite ultrafiltration polysulfone membrane. The preparation of the composite membrane included coating and cleaning. The polysulfone membrane was first immersed in dopamine solution at the concentration of 2 g/L for 12 hours in a concussion incubator. The coated membrane then underwent vibration cleaning with deionized water for 24 hours. Infrared spectroscopy analysis showed that dopamine polymerization formed on the surface of the polysulfone membrane. The contact angle was 63° which was 21° smaller than the basal membrane. The hydrophilism of the composite membrane was significantly increased compared to the basal membrane. The results of separation experiments with aquaculture wastewater showed that under the pressureof 0.10 MPa the removal rates of TSS and COD were 100% and 83.3% respectively, indicating high-quality wastewater treatment.