Friction is two faces, one is helpful for human beings, and the other is harmful, which can make a lot of loss for materials, energy, sizes and so on. Lubrication is an effective way to reduce friction by various kinds of lubricants. Among them, liquid lubrications are the most used due to their excellent properties, compared solid lubricants. Once water was mixed into the liquid lubricant, it will largely reduce the lubrication efficiency by hindering the formation of lubrication films and forming more serve corrosion wear for metal frictional pairs. How to remove water from liquid lubricants is still a challenge for us. Herein, some interesting researches will be introduced, which were done in our research group in the past six years. This will open a new route for the separation of oil/water mixtures.