The present invention relates to preparation of bioimplantable oxygen-generating hydrogel. The novel form of oxygen-generating in-situ crosslinked hydrogel thus prepared forms hydrogel by inducing ionic bonds with negatively charged polymers due to calcium ions emitted from disintegration of hydrogen peroxide, and further generates and emits high-concentration oxygens within the hydrogel. Further, among existing studies that form hydrogel using alginate, the present invention is novel in terms of using hydrogen peroxide in the production of hydrogel for the first time; can address the limitations in existing oxygen delivery systems; can produce bioimplantable oxygen-generating hydrogel by a simple and rapid process without chemical synthesis; and can conveniently control the physical/chemical/biological characteristics of hydrogel according to manufacturing conditions.(AA) Natural alginate main chains(BB) Formation of oxygen-generating in-situ hydrogelCOPYRIGHT KIPO 2019