Oily wastewater produced from various industries and oil spills has posed serious threats to the environment and human health. Promisingly, superwetting materials emerge as great candidates for efficient oil/water separation. In this work, a superhydrophilic-superoleophobic melamine sponge was prepared using a facile immersion method. Methyltrimethoxysilane (MTMS) was used as a binder, which combined fluorosurfactant (FS-50) and TiO2 onto the sponge surface. The coated sponge displayed a water contact angle of 0° and an oil contact angle of 154.5°. Accordingly, it exhibited absorption capacities of above 86 g/g for water and under 1 g/g for oils. Based on its selective permeability and 3D porous structures, the coated sponge could continuously separate various immiscible oil/water mixtures and oil-in-water emulsions with separation efficiencies larger than 99.4 % and 98.7 %, respectively. Notably, the superhydrophilic-superoleophobic sponge was extended to present opposite wettability towards polar and nonpolar liquids. Consequently, it achieved continuous separation of immiscible oil/oil mixtures, with separation efficiency over 99.1 %. Additionally, the coated sponge displayed excellent reusability, great mechanical stability against compression and abrasion, and stable separation performance for various harsh oil/water mixtures. The study presented a promising separation candidate for future applications in oily wastewater treatment and other liquid/liquid separation fields.