A degradable, anti-adhesion double-layer dura mater patch and a preparation method thereof, the double-layer dura mater patch includes a dense layer and a porous layer; the dense layer faces the brain tissue side when the patch is used, It is used to prevent cerebrospinal fluid leakage, prevent brain tissue adhesion, and can be sutured; the porous layer faces the side of the skull when the patch is used, and is used to support the growth, migration, proliferation and differentiation of autologous dura mater cells, and promote autologous dura mater cells. The meninges are regenerated, and after hydrogelation, a tissue adhesive effect is produced to improve the sealing density. The dura mater patch has good flexibility, good mechanical properties and tissue compatibility, can significantly promote the regeneration of damaged meningeal tissue, has anti-adhesion and biodegradable properties, is easy to store, disinfect and prepare before surgery, and fully utilizes biological polysaccharides. The advantages of the material in tissue repair are extremely valuable.