Structure used for cleaning exhaust duct online by means of dry ice

The invention relates to a structure used for cleaning an exhaust duct online by means of dry ice. The structure comprises a crawling mechanism, a spraying nozzle mechanism, an electrical equipment control box and a dry ice storage box, wherein the dry ice storage box is connected with the spraying nozzle mechanism through a dry ice conveying pipe; the electrical equipment control box is used forcontrolling the crawling mechanism to move forwards and backwards and controlling the spraying nozzle mechanism to start and stop; and the crawling mechanism is used for bearing the spraying nozzle mechanism and crawls in the exhaust duct, so that the spraying nozzle mechanism performs cleaning work on the exhaust duct conveniently. According to the structure, the crawling mechanism crawls in theexhaust duct, during crawling, the spraying nozzle mechanism sprays dry ice to the inner wall of the exhaust duct, the dry ice makes violent contact with tobacco tar on the inner wall of the exhaust duct under the normal press