Abstract: With 4-methylcatechol as raw material, through oxidation, esterification reaction, the target compound ethyl 3, 4-dihydroxybenzoate was synthesized and characterized by IR, ¹H NMR and ¹³C NMR. Through a series of experiments, in the oxidation reaction the influence of dosage of catalyst TBAB and potassium permanganate, reaction time and reaction temperature on the yield of 3, 4-dihydroxybenzoic acid were investigated. In the esterification reaction, the influence of dosage of catalyst, TsOH and ethanol, reaction time and reaction temperature on the yield of ethyl 3, 4-dihydroxybenzoate were probed. Under the optimal conditions, the yield of 3, 4-dihydroxybenzoate was 90.5%. The experiment showed that the synthesis method could enhance yield. It decreased the cost of production.It posscssed good prospect for its industrial application.