Abstract: Production techniques of hydroquinone，such as oxidation of aniline，peroxidation of p-diisopropylbenzene，decomposition of bisphenol A and hydroxylation of phenol were reviewed. Hydroxylation of phenol showed good prospect because of its advantages of good product quality and no pollution. The properties and characteristics of these catalysts including inorganic acids，inorganic salts，molecular sieves，heteropoly compounds and composite metal oxides were analyzed and compared. It was found that iron-based composite catalyst represented the trends of development because of its low price and good properties. The research progress of the formation，removal and comprehensive utilization of tar，the development of reactors of different catalysts and high activity iron-based composite catalyst in continuous stirred tank reactor were introduced.