Method for absorbing acrylonitrile

The invention relates to an absorbing method for acrylonitrile, and mainly aims at solving the problems that in the prior art, the absorption water consumption is high, and the concentration of the acrylonitrile in absorption liquid is low. According to the technical scheme, the method comprises the steps that gas-phase raw material flow containing the acrylonitrile and the like and liquid-phase raw material flow enter the bottom and the middle of a first absorption tower respectively, gas-phase material flow III is separated out at the tower top, and absorption liquid of the first absorption tower is extracted from the tower bottom of the first absorption tower; the absorption liquid of the first absorption tower serves as cyclic absorption liquid of the first absorption tower to be circularly cooled and then returns to the middle of the first absorption tower; the gas-phase material flow III enters the bottom of a second absorption tower, after poor water absorption and cold energy recovery are performed in the second absorption tower, light components of the second absorption tower are exhausted, and tower bottom liquid of the second absorption tower returns to the tower top of the first absorption tower. Accordingly, the problems are better solved, and the method can be applied to industrial production for preparing acrylonitrile through propylene ammoxidation.