Abstract: The present application discloses a biological valve material which is a swim bladder derived biological valve material. The present application also discloses a method for preparing the biological valve material, includes: decellularizing a raw swim bladder; and cross-linking the decellularized swim bladder with a cross-linking agent. The present application also discloses use of the biological valve material, wherein the biological valve material is used for preparing one or more of a biological heart valve, a biological patch, and an artificial blood vessel. The present application also discloses a cross-linking agent for a bio-based material, including a cross-linking compound and an organic solvent. The cross-linking compound includes a polyphenol compound. The present application also discloses use of the cross-linking agent, wherein the cross-linking agent is used to cross-link the bio-based material after the decellularization treatment.