Silk fibroin is the main component of silkworm silk. A single silk filament is formed by bonding two parallel silk fibroin monofilament fibers, and the substance in the middle and outer periphery of the fibers that plays a role in bonding and wrapping is sericin. The content of silk fibroin protein accounts for 70–80% of silk, while sericin protein accounts for 20–30%. The silk fibroin obtained by removing sericin from silk contains 18 types of amino acids, including 8 essentials for the human body. Among them, amino acids such as glycine, alanine, serine, tyrosine, which have moisturizing and radiation protection functions, account for more than 80% of the total 18 types of amino acids. This high content of amino acids endows silk fibroin with excellent biological properties and diverse application potential.