Nitrobenzene washing method with low alkali consumption and low sodium salt residue

The invention provides a nitrobenzene washing method with low alkali consumption and low sodium salt residue, which comprises the following steps: two-stage alkali washing is adopted, the first-stage alkali washing is used for neutralizing residual sulfuric acid, trinitrophenol and most of dinitrophenol, the second-stage alkali washing is used for reacting to remove residual dinitrophenol and mononitrophenol, and finally, the residual salt content is removed through neutral water washing; a refined nitrobenzene product is obtained. According to the method, alkali liquor waste is avoided through segmented alkali washing and accurate control of the addition amount of the alkali liquor, the alkali consumption is reduced by 50% compared with that of a traditional washing process, and the residual amount of sodium salt in refined nitrobenzene is reduced to 2 ppm or below. The method provided by the invention can reduce the alkali consumption of the system under the condition of not increasing the amount of wastewa