The present invention relates to a cross-linked sodium hyaluronate gel for tissue filler for plastic surgery and the preparation method thereof. The alkaline solution of sodium hyaluronate reacts with the long chain alkane containing epoxy group and the cross-linking agent containing epoxy group for 2˜5 hours at 35° C.˜50° C. to produce cross-linked sodium hyaluronate, then washed, gelled and sterilized, to prepare the gel. Among which, the molar ratio of sodium hyaluronate:cross-linking agent containing epoxy group:long chain alkane containing epoxy group is 10:4˜1:1˜4 the number of carbon atoms of the said long chain alkane containing epoxy group is 6 to 18. The gel prepared in the present invention can, on one hand, effectively enhance the resistance to enzymolysis to become more stable, and on the other hand, maintain the excellent biocompatibility of sodium hyaluronate without affecting its injectability.
