The research results of magnesium alloys and their applications to the special components are introduced. A new kind of coat system of magnesium alloy was studied, and its conversion film is chromium-free favourable to environment. The base coat and top-coat with good properties were made with special anticorrosive pigments and fillers. The IPN technology was utilized. The coat system passed salt spray test of 700 hours. By microplasma oxidation coating as foundation bed, the fluoropolymer is indrafted through hot-dip and second electrolyzation. By vacuum heat treatment the wear-resistant,corrosion-resistant,hard synergistic coating is formed. Its thickness is 15 similar to 25 mu m, hardness is 340 similar to 370HV0.05 The strain and stress change of deformation in different original textures, the microstructure evolution in deformation of high temperature and low temperature are analyzed. The strengthing by texture was testified. By isothermal forming, casting, etc, some special components are deformed and manufactured, such as water pipes, cartridge receiver, cover plate, filter shell etc. By putting components in the typical natural environment testing fields the adaptability to environment was studied. Some special components such as cabin framework have been tested.