Smart materials with reversible wettability have attracted a lot of attention for application in sewage treatment. In this work, a pH-responsive polymer was prepared via the one-step free radical polymerization of 3-(trimethoxysilyl) acrylate and 2-dimethylaminoethyl methacrylate. The obtained pH-responsive polymer was then coated with a hydrogenated styrene–ethylene–butadiene–styrene block copolymer to endow the material with pH-responsive switchable superhydrophilic and superhydrophobic properties. Due to the excellent self-cleaning and mechanical stability of the coating, it was used to modify paper, which was then successfully utilized in the treatment of oily wastewater, showing great potential for use in advanced applications.