A smart deodorization device with a cover plate includes a reaction chamber having a reaction cavity; an air extraction unit, configured for extracting odor in or near a toilet pool into the reaction cavity; and a water supply unit, configured for supplying water to the reaction cavity. When working, the air extraction unit extracts the odor into the reaction cavity, and the odor is mixed with the water in the reaction cavity to be converted into purified gas and then discharged from the reaction cavity. By using the characteristic that ammonia molecules in the odor are easily soluble in water, the odor and water are mixed in the reaction cavity and then discharged to realize the gas purification. Thus, the device has obvious effects, simple structures, lower costs, and convenience to use without need of replacing filtering materials.