Abstract: Micro-nano superhard TiAlSiN is nitride coating with high hardness, good wear resistance, good adhesion resistance and strong chemical inertia. It coated on cutting tools for machining stainless steel, superalloy and superhard materials. The preparation methods, the factors affecting the internal structure, the hardness, friction, wear, oxidation resistance, cutting performance, anti adhesion and application of TiAlSiN coating are reviewed. In addition, the development trend of micro-nano super hard TiAlSiN coating is prospected.