The invention relates to the technical field of skin care products, in particular to a composition for promoting multi-dimensional defense and repair of skin and a preparation method thereof. The composition is prepared from the following effective components in parts by weight: 0.01 to 20 parts of carnosine, 0.01 to 10 parts of serine, 0.01 to 10 parts of glutamic acid, 0.01 to 10 parts of acetyl hydroxyproline, 0.001 to 1 part of palmitoyl tripeptide-5, 0.01 to 15 parts of hydrolyzed collagen, 0.01 to 10 parts of vitamin B12, 0.001 to 1 part of dipeptide diaminobutyryl benzyl amide diacetate, 0.001 to 1 part of arginine / lysine polypeptide, 0.01 to 15 parts of phytol and 0.01 to 15 parts of isomalt. After the composition is subjected to freeze drying treatment, the activity of the effective components can be ensured, and the preservation time is greatly prolonged. The composition has obvious skin repairing and anti-aging effects, and has multiple effects of resisting oxidation, removing yellowness, brightening skin, tightening skin, resisting wrinkles, moisturizing, promoting cell regeneration, improving skin elasticity, reducing skin roughness, repairing skin barrier, uniformizing skin color and the like.