Methyl salicylate, acetic acid and trioxane were used as raw materials and catalyzed by the concentrated sulfuric acid to produse 5,5'-methylenedisalicylic acid. The intermediate product was then hydrolyze, filtering, drying to gain the ligand 5,5'-methylenedisalicylic Acid with a total yield of 80.4%. The product was confirmed by melting point, and its structure was characterize by 1H NMR and IR spectra.