This invention discloses a preparation method for biocompatible rapid-gelatinghydrogel. Wherein,hydrogel is formed by rapid chemical-crosslinking using the mixing andchemical-crosslinkingreaction under specified conditions between several active compoundcomponents. The preparationmethod comprises the following steps: (1) The solution containingbiocompatible thiolatedmacromolecular derivatives (component A) and biocompatible thiol reactivecrosslinking agents(component B) mutually mix to form reactive mixture with specifiedcrosslinking conditions； (2)the reactive mixture forms the hydrogel. The invention also discloses apreparation method fornovel rapid-gelating hydrogel spray and an application in medical field. Thisinvention has theadvantages of good biocompatibility, no by-products, good stability,convenient use, small amountof raw materials used, suitable for many medical application, etc..
