Compared with traditional biomedical metal materials, such as titanium alloys, stainless steels, cobalt-base alloys, magnesium alloys not only possess biodegradable properties, but also its elastic modulus is close to human bone, so it is hard to induce the effect of ing", so it is known as "new generation of advanced biomaterials". However, the degradation rate of magnesium alloy in human body is too fast, resulting in mechanical instability and metabolic absorption of excessive degradation products in vivo, which limits its application in the field of surgical implant and intervention. Biodegradable or absorbable natural and synthetic polymers are a kind of biomedical materials with light weight, multi-function and good biological safety. If they are used as special protective coating on the surface of degradable magnesium alloys and deal well with the biological function and mechanical compatibility of surfaces between them, it will be important direction to develop advanced magnesium alloys materials and their applications. In this paper, the latest research progress of biodegradable natural and synthetic polymer coatings on magnesium based alloys is reviewed, and the development trend of its research and development and application in the future is put forward.