The invention discloses an absorbable biological membrane as well as a preparation method and application thereof. The absorbable biological membrane is obtained by cross-linking collagen, cellulose derivatives and other polysaccharide substances by using a cross-linking agent. The absorbable biological membrane is obtained by utilizing a double-crosslinking technology, has the advantages of strong mechanical property, soft texture, toughness, low immunogenicity, controllable degradation and the like, has certain viscosity, can be effectively attached to a use part, is widely applied to the field of oral medicine such as periodontology, oral implantation and alveolar surgery, and has a wide application prospect. Moreover, the absorbable biological membrane can stabilize the bone grafting particles, so that the displacement of the bone grafting particles is avoided, the osteogenesis quality is improved, and the survival rate of the implant is greatly improved.