The invention relates to a method for realizing desulfuration, denitration and demercuration through the combination of 
ozone and radiated peroxides. The method comprises the following steps: SO2, NO and Hg<0> from a discharging source are pre-oxidized by 
ozone in a 
flue and are transformed into SO3, NO2 and Hg<2+>; 
ultraviolet lamps radiate 
ultraviolet light, the 
ultraviolet light stimulates peroxides to generate 
sulfate radicals and hydroxyl radicals so as to further oxidize SO2, NO and Hg<0>, and SO3 and NO2 which are generated through oxidation of 
ozone, wherein the reaction products are mainly 
sulfuric acid, 
nitric acid and 
divalent mercury ions, which can be used as resources. Devices for realizing the method mainly comprise the discharging source, a blower, a dust remover, a fume cooler, an 
ozone generator, a longitudinal opposite-spraying atomization 
bed, circulating pumps (I and II), a filler layer, ultraviolet lamp tubes, atomizing nozzles, a 
demister, a 
liquid tank and an after-
treatment system of reaction products. A novel fume purifying 
system adopted by the method can efficiently remove the SO2, the NO and the Hg<0> in the fume, the process of removal does not generate secondary 
pollution, so that the novel fume purifying 
system has an extensive application prospect.