The present invention relates to the field of medicinal synthesis, and discloses a method for synthesizing degarelix. The method of the present invention as a whole divides the synthesis of degarelix into two parts from amino acids at positions 5 and 6, employs proper protective groups in part of the protected amino acids therein, and finally uses in association with a specific acidolysis agent to complete the whole synthesis process. In the present invention, a proper synthesizing scheme is selected, and adaptive protective group and acidolysis agent are selected, so that the overall synthesis process is optimized, the purity of degarelix is significantly improved with a higer total yield, and the production of the toxic hydantoin degradation product is avoided.