A hydrogel based on a cross-linked γ-polyglutamic acid and ε-polylysine polymer is obtained by cross-linking of γ-polyglutamic acid with ε-polylysine, and it is a polymer having the following constitutional unit, wherein, m is a natural number of 15 to 45, n is a natural number of 3900 to 17000, and x is a natural number of 5 to 40. It also discloses a preparation method of as-described hydrogel and its application in preparation as a medical wound dressing.
