The invention relates to the field of skin care products, and particularly discloses a bilberry water-light composition and a preparation method thereof. The bilberry water-light composition comprisesa skin base solution and essence oil; the skin base solution is prepared from the following raw materials: water, propylene glycol, trehalose, a radix salviae miltiorrhizae extract, a bilberry fruitextract, a liquorice root extract, a chondrus crispus extract, a willow flower/leaf/stem extract, aloe vera leaf juice, oat beta-glucan, 1, 2-hexanediol and ethylhexylglycerin; and the essence oil isprepared from squalane, jojoba seed oil, a bilberry fruit extract, sweet almond oil, caprylic/capric triglyceride, plant seed oil, haematococcus pluvialis oil, olive fruit oil, oat kernel oil, plant essential oil and bisabolol. The bilberry water-light composition disclosed by the invention has good long-acting moisturizing effect, and has the effects of moisturizing, moistening and resisting aging on the skin.