The complete ACTH is a peptide composed of 39 amino acids, and the 1-24 peptide sequence fragments in the ACTH structure are the central region of biological activity, and the remaining amino acids play a protective role. The biological effects of ACTH (2-24) are closely related to shock and neuroendocrine and immune activities. As for ACTH (2-24) in peptide synthesis, because Pro is the first amino acid connected to the resin carrier, it has higher requirements for the experiment.