本发明提供卢一种具有保护层的完全可降解镁合金支架载药涂层的制备方法，其包括如下步骤：分别制备保护层聚合物溶液和载药层聚合物材料；将所述保护层聚合物溶液涂覆于镁合金支架表面，干燥后形成保护层；将所述载药层聚合物溶液涂覆于保护层表面，干燥后形成载药层。本发明的聚合物涂层为多层结构，内层是保护层，外层是载药涂层。药物释放后，载药涂层中出现孔洞，影响其致密性从而降低涂层对基体的保护作用，而保护层的存在可以在支架基体与不致密的载药涂层之间形成一层阻隔，从而降低局部腐蚀，减缓支架的降解。

The invention provides a preparation method of drug-loading coating for a fully degradable magnesium alloy stents with a protective layer, which comprises the following steps: preparing a protective layer polymer solution and a drug-loading layer polymer material respectively; The protective layer polymer solution is coated on the surface of the magnesium alloy, and the protective layer is formed after drying; The polymer solution of the drug carrier layer is coated on the surface of the protective layer, and the drug carrier layer is formed after drying. The polymer coating of the invention is multilayer structure, the inner layer is a protective layer, and the outer layer is a drug-carrying coating. After drug release, holes appear in the drug-loading coating, affecting its compactness and thus reducing the protective effect of the coating on the matrix. The existence of a protective layer can form a barrier between the matrix and the non-dense drug-loading coating, thus reducing local corrosion and slowing down the degradation of the scaffold.