The invention discloses an anti-oxidation moisturizing essence rich in fermented products of Vitella hyalineus and a preparation method thereof, belonging to the technical field of cosmetics. The moisturizing essence is composed as follows in parts by weight: 60-80 parts of pure water, 60-80 parts of transparent vitriol Bacteria fermentation product 3‑6 parts, tremella polysaccharide 5‑8 parts, pantothenic acid 0.05‑0.2 parts, tea extract 0.5‑2 parts, purslane extract 1‑3 parts, ascorbic acid 1.5‑3 parts, seaweed extract 2‑ 5 parts, 0.01-0.06 parts of carbomer, 1.5-3.5 parts of squalane, 2-5 parts of propylene glycol, 0.35-0.5 parts of phenoxyethanol, 0.05-0.15 parts of essence. The present invention is not only oriented to improve the polysaccharide product, but also significantly improves the antioxidant activity of the fermented product of Vitella hyaline through the selection of different carbon sources, nitrogen sources, salt solutions and enzymes in the culture medium, and aims to significantly improve the concentration of the essence through the fermentation method. Antioxidant, at the same time, the addition of tremella polysaccharide, tea extract, purslane extract and other compounds significantly improves the effect of moisturizing essence to delay skin aging and make the skin smooth and shiny.