The oxidation of coal in supercritical water was explored by using H2O2 as the oxidant source in a bench-scale semicontinuous installation. The conversion and kinetics of coal oxidation in supercritical water (SCW) medium were investigated. The reaction parameter effects on the conversion and kinetics of coal supercritical water oxidation (SCWO) were determined. Increasing temperature, H2O2 concentration, or the flow rate of H2O2 solution enhances the oxidation of coal in SCW. The oxidation of coal in SCW is a pseudo-first-order process.