The development of highly efficient polymeric membranes with super-wetting surfaces (superhydrophilic/submerged superoleophobic) is one of the ideal options to achieve emulsified oily wastewater separation. However, this remains a challenging due to low fluxes and severe membrane contamination limitations. Here, we have demonstrated an ultra-hydrophilic, underwater super-oleophobic, highly anti-fouling and antibacterial (polydopamine/poly [2-(methacryloyloxy) ethyl] dimethyl- (3-sulfopropyl) ammonium hydroxide) PDA/PSBMA modified membrane by grafting amphoteric polymers via atom transfer radical polymerization (ATRP). Benefiting from PSBMA's superhydrophilicity and the unique adhesion of dopamine (DA), the PDA/PSBMA modified membrane shows superhydrophilic properties, superoleophobicity underwater, oil resistance, and fouling resistance. Meanwhile, PDA/PSBMA modified membrane reached a superb permeability to water as high as 5620 L·m−2·h−1·bar−1 and remarkable oil rejection rate of 98 % in separating diesel-in-water emulsions. Furthermore, the separating performance remained fairly constant over 10 emulsion filtration cycles. Besides, the PDA/PSBMA modified membranes have excellent acid and alkali resistance and antibacterial properties, showing its potential for oily wastewater purification. This work offers a simple and versatile strategy to fabricate superwetting efficient polymeric membranes to separate emulsified oily wastewater.