The invention discloses a soot blowing system of a denitrification reactor. A catalyst layer is arranged in the denitrification reactor; the soot blowing system comprises a soot blower, a compressed air supply device and a plasma reaction device, wherein the soot blower is positioned in the denitrification reactor; the soot blower is provided with at least one spray nozzle device; the compressed air supply device is connected with the soot blower through a compressed air pipeline which is provided with a first valve; the plasma reaction device is connected with the soot blower through a plasma pipeline which is provided with a second valve; the compressed air supply device is used for conveying compressed air to the soot blower through the compressed air pipeline for blowing the catalyst layer; and the plasma reacting device is used for conveying plasmas to the soot blower for blowing and regenerating the catalyst layer. The soot blower is separately connected with the compressed air supply device and the plasma reaction device, so that the catalyst can be blown and regenerated, and therefore, the catalytic efficiency of the catalyst is improved, and the service life of the catalyst is prolonged.