Lactobacillus casei is a widely distributed lactic acid bacterium commonly used in the production of fermented dairy products such as cheese and yogurt. Some strains are also used as probiotics. Lactobacillus fermentation lysate contains a series of probiotic active ingredients obtained during the fermentation process of Lactobacillus casei. These active ingredients include peptidoglycan, teichoic acid, protein, phospholipid, sterol, fatty acid, enzymes, peptide, amino acid, nucleotide, extracellular polysaccharides and so on. These can create a good growth environment for beneficial skin bacteria, thereby maintaining a balanced state of the skin, alleviating various problems and achieving skin care effects.