The invention discloses moisturizing stock solution. The moisturizing stock solution comprises a component A, a component B, a component C and deionized water, wherein the component A contains propylene glycol, glycerol, xylitol, hydroxyethyl cellulose, Carbomer and hyaluronic acid; the component B contains triethanolamine; and the component C contains panthenol, polyglutamic acid, glyceryl polymethacrylate, aloe extract, hamamelis virginiana extract, purslane extract, hydrolysis pome cactus flower extract, glycine, caprylhydroxamic acid, hydrogenated castor oil and pelargonium graveolens leaf oil. The moisturizing stock solution disclosed by the invention is added with plant moisturizing and hydrating ingredients, and achieves good face skin moisturizing and hydrating effects, so that skin is fine, smooth, transparent and like new; meanwhile, an additive-free preservative is used, so that face skin is not stimulated, and worries of a customer are eliminated. The invention also discloses a preparation method of the moisturizing stock solution with simple technology, high production efficiency and no environmental pollution.