Provided is a preparation method of a porous hyaluronic acid sponge comprising the steps of: dissolving hyaluronic acid in an aqueous sodium hydroxide solution; adding an epoxy-based crosslinking agent to the resultant aqueous sodium hydroxide solution in which hyaluronic acid is dissolved and homogenizing the hyaluronic acid solution; hydrogelating the homogenized hyaluronic acid solution; washing the hydrogelated hyaluronic acid hydrogel with ultrapure water; swelling the washed hyaluronic acid hydrogel to attain porosity; and freeze-drying the hyaluronic acid hydrogel to obtain a porous hyaluronic acid sponge.