A process for the preparation of crosslinked hyaluronic acid hydrogel suitable for soft tissue augmentation is disclosed, wherein said process comprises:(a) hydrating sodium hyaluronate fibers in a sodium hydroxide solution to produce hydrated sodium hyaluronate fibers； and (b) contacting the sodium hyaluronate fibers with a polyethylene glycol-based epoxide crosslinking agent to create a crosslinked hyaluronic acid hydrogel suitable for soft tissue augmentation, wherein the polyethylene glycol-based epoxide crosslinking agent has two to six reactive groups for linking to hyaluronic acid side chains, preferably the polyethylene glycol-based epoxide crosslinking agent is tetrafunctional.
