The invention discloses a method for degrading low molecular weight organic matter in regeneration wastewater of waste flue gas denitration catalyst, which comprises the following steps: step 1, wastewater pretreatment; step 2, anaerobic hydrolysis treatment; step 3, aerobic treatment and step 4, disinfection drainage. During step 1, the regeneration wastewater of waste flue gas denitration catalyst is guided into an electrochemical apparatus to subject to electroflocculation oxidation coupling reaction after hydrogen peroxide is added into the electrochemical apparatus, setting is perfomed after the reaction is ended, the sludge obtained by setting is discharged outside, the supernate obtained by setting is pumped out by a water suction pump and discharged into a anaerobic digestion reaction tank. According to the method provided by the invention, the mineralization efficiency of the organic pollute is greatly improved, the process cost is reduced, tiny particulate matter is promotedto subject to flocculent setting and the oragnic matter is subject to degradation more fully.