Method of liquid sulfonation in o-dichlorobenzene as a solvent was used in place of solid baking sulfonation. Sodium 1-amino-4-naphthalene sulfonate was prepared through ammonium salifying by 1-naphthylamine and sulfuric acid, transposition sulfonation and salifying(Na2CO3) in the presence of Tween 60 as a surfactant and o-dichlorobenzene. Effects of the solvents, the sulfonation reaction time, surfactants, recycle times of mother liquor were investigated. The optimum conditions were found as follows: 1-naphthylamine 35.8g, 80% sulfuric acid 33.6g, o-dichlorobenzene 150mL, Tween 60 1.5g, sulfonation time 6h, yield of sodium 1-amino-4-naphthalene sulfonate 90.6%.