Belonging to the technical field of arginine protection, the invention relates to a synthesis method of Fmoc-Arg(Pbf)-OH. The synthesis method of Fmoc-Arg(Pbf)-OH includes: first performing carboxyl esterification on arginine, then introducing a Boc group to protect amino thereon, introducing a Pbf group to guanidine, removing the Boc group, conducting saponification, and finally introducing a Fmoc group to the amino. According to the method for synthesis of Fmoc-Arg(Pbf)-OH, with only 1.1 times of Pbf-Cl, Arg can react totally, compared with the prior art that unreacted arginine still exists when the dosage of Pbf-Cl is 2 times that of arginine, the dosage of Pbf-Cl in the invention is greatly reduced, also no Arg residual exists, and the Pbf-Cl is expensive, therefore the cost is greatly reduced, thus being conducive to industrial popularization and application.