Disclosed are low-modification biocompatible high polymer sulfhydryl-modified derivatives. The derivatives have a very low degree of sulfhydryl modification, and maintain to the greatest extent possible the initial structure, physiological function, and biocompatibility of the biocompatible high polymer. At the same time, the sulfhydryl introduced effectively carries out chemical cross-linking so as to produce a biocompatible high polymer cross-linked material having a low degree of cross-linking. Also disclosed is a type of disulfide cross-linked biocompatible high polymer cross-linked material. This cross-linked material has a low degree of cross-linking and not only maintains to the greatest extent possible the initial structure, physiological functions, and biocompatibility of the biocompatible high polymer, but also delays metabolization of the biocompatible high polymer in the body and reduces solubility. This satisfies a variety of needs in terms of clinical application. The present invention relates also to the use of disulfide cross-linked biocompatible high polymer cross-linked material in medical science and pharmacology.