The photocatalytic degradation of organophosphorous pesticide residues in pakchoi by TiO2-ZnO complex nanomaterials was investigated in this paper.We took four organophosphorous pesticides in common use as researching object and obtained the results showing that different pesticides were removed at different rate.The average removal rate of the 4 kinds of pesticides residue was more than 40% after 1h and more than 80% after 5h.The removal effect of the isocarbophos was the best compared to the average residue removal percentage.The concentration of pesticide residues in pakchoi was higher,the degradation rate of pesticide residues in vegetable was lower.When the original concentration of the organophosphorous pesticide was 5 mg/L,the kinetic equation for photocatalytic degradation was derived as ln(C0/Ct) =kt + B,which fitted in with the first-order kinetic model.