The invention belongs to the field of health care products, and particularly relates to a composition and a preparation method and an application thereof. The invention provides a composition which isprepared from the following raw materials: collagen, gamma-aminobutyric acid, chitosan oligosaccharide and yeast extract. The invention also provides a preparation method of the composition. The invention also provides an application of the composition or a product obtained by the preparation method in reduction of the content of advanced glycation end products (AGEs) in organisms. The test measurement shows that the product prepared according to the technical scheme provided by the invention can effectively reduce the content of the AGEs, also has an oxidation-resisting effect, and further can achieve the effect of preventing skin aging; and furthermore, the product prepared by the preparation method provided by the invention is low in cost, simple in preparation method and suitable forlarge-scale popularization. The technical scheme provided by the invention solves the technical defects in the prior art that products for inhibiting expression of the AGEs cannot give consideration to good effect and low price.