Catalytic oxidation desulfurization of gasoline liquefied petroleum gas (LPG) is a key process for the utilization of petroleum hydrocarbons. However, the inherent mechanism remains unclear and the kinetic investigation is usually performed in processes with limited mass transfer rates. Herein, the kinetics and mechanism of catalytic oxidation of sodium ethyl mercaptide were investigated with microfluidics. The effects of temperature, pressure, residence time, and gas‐liquid flow ratio on the oxidation were assessed on the basis of eliminating mass transfer resistance. According to the results of UV‐vis spectra and binding constant, it was confirmed that the catalytic center was in the form of the dimer. A heterogeneous reaction kinetic model was proposed as such. The kinetic parameters close to intrinsic kinetics and corresponding kinetic rate expression were obtained.