The invention relates to chlorinated cardanol. The chlorinated cardanol has the structural formula shown in the specifications, wherein n is more than or equal to 1 and less than or equal to 4. The invention also provides a method for preparing the chlorinated cardanol. The method comprises the following steps of: putting cardanol into a reaction tower; adding a catalyst into a chlorination tower; adding liquid chlorine into a vaporization tank for vaporizing and then adding the vaporized liquid chlorine into a buffer tank; metering the liquid chlorine with a flow meter and feeding the metered liquid chlorine into the reaction tower; controlling the reaction temperature to be between 50 and 110 DEG C and reacting for 5 to 12 hours; and pressing a chlorinated product of the reaction tower into an acid removing kettle with compressed air for removing acid so as to obtain the chlorinated cardanol. Due to the adoption of a non-solvent chlorination reaction, the chlorinated cardanol has the advantages of simple equipment, small investment, no three-waste pollution, light product color, low inorganic salt content and recyclable byproducts.