Abstract: In order to improve the degradation efficency of acephate residue, the effects of H2O2, metal ions, gas ratio, ethanol, ketone or the combination of H2O2 and metal ions on the photodegradation efficiency of acephate by UV TiO2 process were examined, based on the former results of photocatalytic degradation of acephate. The results indicated that the addition of gas with higher oxygen ratio, H2O2, Fe3+ or Cu2+ were favorable for the degradation. While the degradation of acephate with the the addition of ethanol or acetone was low. The optimum conditions was as follow: the initial concentration of acephate 20 mg/L, concentration of TiO2 0.1 g/L, temperature of 25℃, pH value of 6.7, concentration of Cu2+ 0.2 mmol/L, concentration of H2O2 10 mmol/L, and bubbling gas composed of N2 and O2 (20:80 ). Under this condition, the degradation rate was 98.03% within 20 min. This study provide a reference for the degradation of acephate residue.