The effects of the main operation variables on the electrochemical oxidation of simulated tributyl phosphate (TBP) waste by a boron-doped diamond anode are individually studied. The optimum operating conditions are obtained as follows: 4 g L−1 initial TBP concentration, 180 min degradation time, 40 mA cm−2 current density, 0.5 mol L−1 Na2SO4 as the supporting electrolyte, and unadjusted pH of the aqueous phase. Under such conditions, a chemical oxygen demand (COD) removal ratio of 82.3% is achieved, and the energy consumption is 26.16 kWh m−3. A degradation mechanism of TBP is tentatively proposed.