NOVELTY - Solid phase synthesis of carbetocin, involves: (a) reacting 4-hydroxymethyl-phenylacetamidomethyl (PAM) resin and Fmoc-Gly-OH to obtain Fmoc-Gly-PAM resin; (b) Fmoc-Gly-PAM resin deprotection; (c) using dichloromethane/triisopropylsilaten/trifluoroacetic acid to remove Cys and Mmt protecting group from BrCH_2CH_2CH 2CONH-Tyr(OMe)-Ile-Gln-Asn-Cys-Pro-Leu-Gly-PAM resin from step (b); (d) cyclization reaction to obtain cyclo(CH_2CH_2CH_2CO-Tyr(OMe)-Ile-Gln-Asn-Cys)-Pro-Leu-Gly-PAM; (e) aminolysis to obtain a carbetocin crude; and (f) purification to obtain carbetocin.    USE - The method is useful for solid phase synthesis of carbetocin (claimed).    ADVANTAGE - The method has a total yield of up to more than 45%, and compared to conventional method, this method avoids the use of high concentration corrosive acid and inflammable and explosive reagents, the yield is high, the cost is low, reaction condition is mild, environment friendly, and good for industrial production.    DETAILED DESCRIPTION - Solid phase synthesis of carbetocin, involves: (a) reacting 4-hydroxymethyl-phenylacetamidomethyl (PAM) resin and Fmoc-Gly-OH to obtain Fmoc-Gly-PAM resin; (b) Fmoc-Gly-PAM resin deprotection by removal of the Fmoc, amino acids are sequentially connected with Fmoc protecting group, to give BrCH_2CH_2CH_2CONH-Tyr(OMe)-Ile-Gln-Asn-Cys(Mmt)-Pro-Leu, the Fmoc protecting group of the amino groups are Fmoc-Leu-OH, Fmoc-Pro-OH, Fmoc-Cys(Mmt)-OH, Fmoc-Asn-OH, Fmoc-Gln-OH; Fmoc-Ile-OH, Fmoc-Tyr(OMe)-OH, Br(CH_2)_3COOH; (c) using dichloromethane (DCM)/triisopropylsilaten (TIS)/trifluoroacetic acid (TFA) to remove Cys and Mmt protecting group from BrCH_2CH_2CH 2CONH-Tyr(OMe)-Ile-Gln-Asn-Cys-Pro-Leu-Gly-PAM resin from step (b); (d) using 4-dimethylaminopyridine (DMAP) as cyclization reagent, and dimethylformamide (DMF) as solvent, and reacting with the product of (c) for cyclization reaction to obtain cyclo(CH_2CH_2CH_2CO-Tyr(OMe)-Ile-Gln-Asn-Cys)-Pro-Leu-Gly-PAM; (e) using methylamine solution for aminolysis of the product of (d) to obtain a carbetocin crude; and (f) purification to obtain carbetocin.