Abstract: The method with 2,4-di-t-amylphenol and anhydrous trimeric acetaldehyde as raw materials，and water containing acid catalyst and surface active agent as reaction solvent，was used to synthesize 2,2′-ethylenebis-(4,6-di-t-amylphenol). The optimum conditions of synthesis were determined as follows：molar ratio of 2,4-di-t-amylphenol and anhydrous trimeric acetaldehyde 2∶1.2，amount of water 180 g，amount of emulsifier 0.5 g，and amount of catalyst 11.0 g at reacting temperature 80～83℃ for 5 h. The process of clean cyclic production was adopted to recycle the reaction solvent，and also resolve the problem of pollution of phenol-containing waste water of traditional production technology. Under these optimal conditions，the yield of the product bisphenol H was over 93.3% and the conversion of 2,4-di-t-amylphenol could be up to 94.3%.