Abstract: A series of macroporous polystyrene grafted with quarternary ammonium salts as tri-phase phase transfer catalysts were prepared for the synthesis of 1,2-ethanedithiol. Factors that influence the reaction were investigated including the type of tertiary amine，reaction temperature，amount of catalyst，molar ratio of 1,2-dibromoethane to sodium hydrosulfide，amount of solvent，pH value and concentration of aqueous solution of NaHS，grinding catalyst or not etc. Proper reaction conditions were obtained based on 0.1mol 1,2-dibromoethane as n(1,2-dibromoethane)∶n(NaHS)=1∶2.2, polystyrene grafted with triethylamine 0.7 g（containing quarternary ammonium salt 0.002mol），toluene 8.6 mL，pH value of NaHS aqueous solution adjusted by NH4Cl to about 12，concentration of NaHS aqueous solution 10mol/L，reaction temperature 75 ℃，reaction time 5.5 h，under which the conversion of 1,2-dibromoethane is higher than 99% and yield of 1,2-ethanedithiol is 50%～55%. The catalyst can be used for five times with no obviously negative effect.