Synthesis method of tilpotide

The invention discloses a synthesis method of tilpotide, and belongs to the technical field of pharmacy. The method comprises the following steps: (1) synthesizing tilpoitide resin by an Fmoc/tBu solid-phase method, firstly synthesizing a main chain from a C end to an N end by taking amino resin as initial resin, then removing a K20 side chain protecting group, and then sequentially coupling all sites of the side chain; (2) coupling the K20 site in the sequence by using a material Fmoc-Lys (R1)-OH (R1 = Alloc or Dde); (3) respectively carrying out coupling on Tyr1 and Aib2 in the sequence, and carrying out coupling on Ile12 and Aib13 in the sequence by using a material Boc-Tyr (tBu)-Aib-OH and a material Fmoc-Ile-Aib-OH; the preparation method comprises the following steps: coupling Glu3 and Gly4 by using Fmoc-Glu (OtBu)-Gly-OH; the Gly29 and the Gly30 are coupled by using Fmoc-Gly-Gly-OH, so that process impurities generated at the site are avoided; (4) cutting the peptide resin by adopting a TFA mixed solut