The invention discloses a digestion method and a digestion device for quickly digesting carbon monoxide, and belongs to the technical field of toxic gas purification. The method comprises the following steps: spraying solid catalyst powder into a carbon monoxide enrichment space so as to oxidize carbon monoxide into carbon dioxide and realize rapid digestion of carbon monoxide by utilizing the mechanical motion or Brownian motion of the catalyst powder and the principle of catalytically oxidizing carbon monoxide by using a catalyst. The device comprises a catalyst powder storage tank, a spraying device, a pressure release valve, a vacuumizing/inflating port and a siphon. The upper end of the catalyst powder storage tank is a tank opening; a material spraying device is arranged on the tankopening; the siphon is positioned in a tank body of the catalyst powder storage tank; the upper end of the siphon is connected with the spraying device, and the lower end extends to the bottom of thecatalyst powder storage tank; and the upper part of the tank body of the catalyst powder storage tank is connected with a pressure release valve and a vacuumizing/inflating port. The method and the device have the advantages of being high in carbon monoxide digestion speed, low in cost and suitable for fire and explosion sites, thereby preventing carbon monoxide from hurting people in distress.