Abstract: Smart materials are materials that have abilitys to sense, respond and adapt to their environments. With the continuous development of science and technology, smart materials are more and more widely used in various fields, and have very broad prospects for development in the future. In this paper, one kind of azobenzene compound containing polymerizable groups was synthesized. This azobenzene compound was used as photoresponsive unit and dimethylaminoethyl methacrylate as a pH responsive unit, they can copolymerize with hydroxyethyl methacrylate to form terpolymer by one step reversible addition-fragmentation chain transfer polymerization (RAFT) method, which has smart dual response to light and pH. When stimulated by different conditions, the maximum contact angle change of the polymer coating can reach 120.2°, and the contact angle can still restore to the initial state after multiple transformations between hydrophilic and hydrophobic. It shows that the material has excellent reversible stimulus responsiveness ability. When the polymer was coated on the non-woven fabric to make light /pH dual-responsive oil-water separation membrane, it can undergo a reversible transition between hydrophilic and hydrophobic, so as to achieve the selective separation of oil and water, the single separation efficiency can reach 96.3% and 95.8%, respec-tively. This kind of stimulus responsibility to light and pH can be used in areas such as liquid transport and oil-water separation in complex environments, and have great potential for smart water-oil separation application.