Multifunctional microfiltration membrane for water decontamination is prepared via one-step assembly coating of dopamine (DOPA) and tannic acid (TA). The DOPA-TA coated membrane with superhydrophilicity and superoleophobicity is capable of emulsion separation and simultaneous heavy metal ions as well as non-metal ions adsorption. Such a facile approach, is the first example for dealing with the complicated contaminants polluted wastewater and has great potential in practical water remediation.