The present invention relates to a mussel adhesive protein-based bioadhesive hydrogel and a manufacturing method thereof. More specifically, to a hydrogel formed by combination of a DOPA (3, 4-dihydroxyphenylalanine) residue included in a mussel adhesive protein and Fe3+ ions. In addition, the present invention relates to a hydrogel formed as a DOPA residue contained in a mussel adhesive protein is oxidized.본 발명은 홍합 접착 단백질을 기반으로 한 생체접착성 하이드로젤 및 이의 제조방법에 관한 것이다.