The invention relates to a control method and a control device for the moisture content of furfural in the extraction of the furfural and a method for preparing aromatic rubber oil. The method for preparing the aromatic rubber oil comprises the following steps of: mixing a part of furfural from a furfural dryingtower with raw oil and enabling the mixture to enter the lower part of an extracting tower; mixing the other part of furfural from the furfural dryingtower with water and enabling the mixture to enter the upper part of the extracting tower; carrying out counter-current contact on the two parts of materials in the extracting tower; and separating raffinate from overhead raffinate. By adopting the control method provided by the invention, the moisture content of the furfural entering the upper part of the extracting tower is controlled between more than 0.5 weight percent and 10 weight percent; and the raw oil is solvent refining extract oil or dewaxed oil of the solvent refining extract oil. The aromatic rubber oil prepared by adopting the method has high yield, the prepared aromatic rubber oil satisfies the directive requirements of European Union 2005 / 69 / EC, and the mass percent of polycyclic aromatic hydrocarbon is less than 3 percent.