The invention discloses a composition for saccharifying and preventing aging and a preparation method thereof. The composition is prepared from the following raw materials in parts by weight: 10-20 parts of lonicera japonica, 2-9 parts of guava leaves, 8-15 parts of radix polygonati officinalis, 3.5-14 parts of mulberry leaves, 7-20 parts of acerola cherry fruit, 12-47 parts of antioxidant substances, 2-9 parts of anti-saccharification substances and 7.76-32.5 parts of a nutritional supplement. The preparation method of the composition for saccharifying and preventing aging comprises the stepsthat a, the lonicera japonica, the guava leaves, the radix polygonati officinalis, the mulberry leaves and the acerola cherry fruit are taken as a product A; b, the product A, water and flavor enzymeare boiled out to obtain a filter residue product B1 and a filter liquor product B2; c, the product B1 is subjected to acetone extraction to obtain a product C; d, the product B2, the product C, theantioxidant substances, the anti-saccharification substances and neutral protease are subjected to homogenization treatment to obtain a product D; e, the nutritional supplement and the product D are mixed and concentrated to obtain a product E; and f, the product E is sterilized, dried and pelletized to obtain a finished product. The composition for saccharifying and preventing aging and the preparation method thereof have the characteristics of an obvious effect and high extraction efficiency of effective components.