The invention provides a synthesis process of 
carbetocin. The synthesis process comprises the following steps: performing a 
coupling reaction on Fmoc-Gly-OH with Rink 
Amide-AM Resin obtained in the first step to obtain Fmoc-Gly-Rink 
Amide-AM Resin; performing deprotection (20% 
piperidine) with DBLK to obtain H-Gly-Rink 
Amide-AM RFesin, and orderly completing the 
coupling of the H-Gly-Rink Amide-AM Resin with Fmoc-Leu-OH, Fmoc-Pro-OH, Fmoc-Cys(Trt)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Gln(Trt)-OH, Fmoc-Ile-OH, Fmoc-Tyr(Me)-OH and tetrachlorobutyric acid until 
carbetocin linear 
peptide resin is synthesized; mixing a 
cracking agent with the 
carbetocin linear 
peptide resin obtained in the fourth step to have a 
cracking reaction, thereby removing the Rink Amide-AM Resin and 
side chain protecting groups; cyclizing the carbetocin linear crude 
peptide into a carbetocin crude product, and separating and purifying the carbetocin crude product to obtain the carbetocin. The synthesis process has the advantages that the 
polymerization side reaction is prevented, the process 
route is greatly simplified, the production cost is reduced and the synthesis efficiency is improved; in addition, the purity of the finished product is high; in short, the synthesis process is convenient for large-scale production, and meanwhile, advantageous for 
environmental protection, and has remarkable economic and 
social benefits.