A biological artificial ligament for reconstructing ligaments of patients with broken ligaments is composed of a substrate (1) made of animal ligaments or tendons, and an active coating (2) coupling on the surface of the substrate (1). The animal ligaments or tendons are immobilized by crosslinking through an immobilizing agent and processed to remove antigens. The active coating (2) contains active components, such as polypeptide or osamine polysaccharid. The preparation method of the biological artificial ligament comprises steps of collecting fresh tendons or ligaments from animals to use as the substrate (1), performing preprocessing, fat and antigens removing, and immobilizing to the substrate (1).
