The invention offers a kind of method which three-induced compound, chloroguaiacol is used as substrate in pulping bleach wastewater; suspension system is used to achieve photoelectrocatalytic degradation. In the condition that applied pressure is from 3 to 5V, ultraviolet wavelength is 253.7nm, power is 30W, the concentration of titanium dioxide catalyst is 250mg/L, the concentrations of aeration and chloroguaiacol are 0.0125mmol/L, circulation flow rate is 20L/h, PH value is 6, room temperature is 20+-8 degree C, and reaction time is from 100 to 120 minutes, the detection result indicates by UV/GC/MS that chloroguaiacol can be completely degraded, doesn't generate intermediate, and degraded substrates are completely mineralized.