The invention belongs to the technical field of organic synthesis, and particularly relates to a phenol and hydrogen peroxide hydroxylation microchannel reaction method. The method comprises the steps of mixing the raw materials phenol, water, hydrogen peroxide and a water-soluble catalyst according to certain proportions to prepare a raw material solution, adding the raw material solution into a mixing tank, setting the reaction temperature of a microchannel reactor to be 30-150 DEG C, and inputting the raw material solution into the microchannel reactor at the flow rate of 5-150 mL/min through continuous charging and discharging for hydroxylation reaction, so that catechol and hydroquinone are obtained. The method is simple, operation is convenient, the conversion rate is high, selectivity is high, efficiency is high, and the content of tar in reaction liquid is low.