Sodium single-fatty alcohol phthalate ester was synthesized with phthalic anhydride and different alcohol under catalyst and then neutralized with sodium hydroxide. The influence of catalyst, alcohol, rate of material, esterification temperature and solvent were investigated, and structure, foam capacity and interface were also studied in the paper. The optimum reaction conditions of esterification condition was catalyst for self-made BN-1, xylene as solvent, n(alcohol):n(phthalic anhydride)=1:1.60, esterification temperature 100℃, esterification time 5h. As the alcohol carbon chain increased, the product of a single phthalate ester sodium salt foam capacity gradually decreased, but the ultra-low interfacial tension increased gradually.