Tachyplesin I is a host defense peptide with strong antibacterial activity. Tachyplesin I is a peptide composed of 17 amino acids. It belongs to a cationic antibacterial peptide. There are two pairs of disulfide bonds in the sequence, forming a very typical cyclic antiparallel β structure. In some studies, Tachyplesin I is the main raw material antibacterial drug, which has a high safety factor and has been used clinically.