Disclosed is a method for preparing a surface coating with a reduced degradation rate of a biodegradable magnesium alloy vascular stent, comprising firstly grafting a silane coupling agent to the surface of a magnesium ally by dip coating, heat curing, and forming a silane coupling agent coating on the surface of the magnesium alloy and then coating a polymer on the surface of the silane coupling agent coating by spin coating, and drying under vacuum to form a polymer coating. The polymer coating on the surface of the magnesium alloy and pretreated by a silane coupling agent can enhance the bonding force with the surface of the magnesium alloy vascular stent to suppress excessive degradation of the magnesium alloy matrix, and improve the biocompatibility of the vascular stent.
