The invention provides a hydrogel dressing and a preparation method thereof. The dressing is prepared from a sea-buckthorn extract, a Chinese atractylode rhizome extract, hyaluronic acid, polylysin, polyhydroxyethyl methacrylate, carrageenan, 2-hydroxyethyl methacrylate, vitamin C, polyvinyl alcohol, calcium chloride, borax, ammonium dihydrogen phosphate, glycerinum, mannose and deionized water. The preparation method comprises the following steps: firstly preparing the sea-buckthorn extract and the Chinese atractylode rhizome extract, respectively, adding such components as hyaluronic acid, polylysin, polyhydroxyethyl methacrylate, carrageenan, 2-hydroxyethyl methacrylate and ammonium dihydrogen phosphate to 1 / 2 parts by weight of ionized water to obtain a mixed liquid I, next, adding such components as vitamin C, polyvinyl alcohol, calcium chloride, borax, glycerinum and mannose to the rest parts by weight of deionized water to obtain a mixed liquid II, and finally, mixing the sea-buckthorn extract, the Chinese atractylode rhizome extract, the mixed liquid I and the mixed liquid II, namely performing a thermal reaction, thereby obtaining the hydrogel dressing. The hydrogel dressing is capable of promoting the healing of a wound, and lasting in antibacterial effect and low in production cost.