Abstract: The invention of biological dura mater patch and a preparation method thereof. Raw material of patch does not come from commercial meat animals, but from breeding animals, such as SIS patch of the sow, has natural good mechanical properties; the method uses plant-derived reagents in the decellularization process, no damage to ECM natural structural base, and retain more active ingredients, has a better ability to induce tissue repair and growth; neither uses a cross-linking agent to enhance mechanical properties, nor synthetic detergents used to remove cells; chemical residues and their toxicity are avoided, while more effective ingredients in ECM, especially GAGs be retained. The patch has soft texture and good toughness, easy to sew tightly, and prevent cerebrospinal fluid leakage; and degradation rate is basically synchronized with the growth of the new dura mater, which is more conducive to repair and regeneration of dura mater.