The invention discloses a restoring serum and a preparing method thereof, and is aimed at providing the serum which can effectively improve the skin permeability, balance the water storage, improve the skin shielding function and relieve and resist inflammation. The restoring serum is technologically characterized by comprising glycerinum or butanediol, erythritol or trehalose, sodium hyaluronate,a natural plant restoring factor, rona care ectoin, a water//butanediol//amino acid compound, a water//lactobacillus/soybean fermentation product extract//butanediol and other components. The invention belongs to the technical field of cosmetics.