The invention discloses a method for synthesizing tetrapeptide isomers by using solid phase peptide. The method includes using any of trityl chloride-type resins as a starting raw material, sequentially linking fmoc-protected amino acids according to the solid phase synthesis method, obtaining tetrapeptide isomer resins, meanwhile sequentially removing fmoc protecting groups, using a condensing agent to perform a peptide synthesis reaction, simultaneously removing side chain protecting groups and cutting peptides after obtaining protected tetrapeptide isomer resins, obtaining crude tetrapeptide isomers, separating and purifying the crude tetrapeptide isomers through C18 or C8 chromatographic column, and then obtaining the tetrapeptide isomers. According to the protected tetrapeptide isomer synthesis method required by the method for synthesizing the tetrapeptide isomers, raw and auxiliary materials are convenient to collect, the process is stable, the production cycle is short, the production cost is low, the yield is high, the purity is fine, the quality is stable, large-scale production can be achieved, and the market competition ability is high.