Oily wastewater seriously endangers human health. Ti3C2Tx MXene has attracted extensive attention as a building block for separating membranes because of its unique two-dimensional structure and excellent hydrophilicity. In this study, we constructed a superwetting Ti3C2Tx MXene membrane intercalated with sodium alginate. The hydrophilic sodium alginate not only enlarged the nanochannel of the MXene membrane but also decorated the membrane surface and endowed the membrane with excellent surface superwetting properties. The underwater oil contact angle (OCA) was about 151°, indicating an extremely low adhesion between oil and membrane surface. The membrane could also separate a series of oil-water emulsions with high separation efficiency and flux. Due to its excellent underwater superoleophobicity, the membrane demonstrated outstanding antifouling property. Excellent separation performance was maintained even after separation cycles. This work provides insights into the rational use of MXene-based membranes design and demonstrates its potential in the field of membrane separation.