The invention relates to a pre-grading reinforced charged friction electric separation device and method. The device comprises a vibration feeder, an air inlet pipe, a first-stage friction belt electrical device, a second-stage friction belt electrical device and a high-voltage electrostatic field, wherein the first-stage friction belt electrical device is connected with the second-stage frictionbelt electrical device through a hose; the second-stage friction belt electrical device comprises an inclined pipeline, the top of the inclined pipeline is sequentially connected with three parallel vertical pipelines from low to high, a corona charged device is installed in the first pipeline, a friction rod charged device is installed in the second pipeline, and a friction pipe charged device isinstalled in the third pipeline; and the bottom ends of the three pipelines are over against the high-voltage electrostatic field. The device is provided with two groups of friction chargers, so thatthe charged requirements of particles with different particle sizes can be met, and the particles can be separated with sufficient charges in the high-voltage electrostatic field. The method has a wide application range, is mainly used for separating complex mineral components, and can also be used for the separation process of plastic particles and powder engineering and even for the separationof cereal and other agricultural products and impurities.