Oxidation is one of the most commonly used unit reactions for the preparation of oxygenated compounds such as phenols, alcohols, aldehydes, ketones, carboxylic acids and anhydrides. It plays a very important role in the production and research of fine organic synthesis. Concentrated sulphuric acid oxidation requires the addition of suitable catalysts, but requires organic materials and oxidation products to have sufficient stability under the reaction conditions. The micro-reactor satisfies stable flow and mass transfer requirements, has sufficient heat transfer area, can remove large amounts of heat released by the oxidation reaction in time, accurately controls the reaction temperature, and shortens the reaction time.