The utility model discloses a three-plate aluminum alloy forging hub, which comprises a front rim plate, a middle spoke plate and a rear rim plate. The middle spoke plate, the front rim plate and the rear rim plate are in interference fit and are in assembling connection through fastening bolts, the outer surface of a joint position among the middle spoke plate, the front rim plate and the rear rim plate is provided with a smooth inwards concave rubber sealing layer formed by inward suction, and inward suction rubber seepage is arranged in clearances at the joint position of the three plates. Sealing process of the three-plate aluminum alloy forging hub sequentially includes a cleaning step, a mounting preparation step, a compaction sealing step, a coating step, a vacuum extracting step and a forming step. The vacuum extracting sealing technology can avoid dead corners during sealing, and rubber can be sucked to seep into the clearances of the joint position of the three plates of the hub. The three-plate aluminum alloy forging hub is fine in sealing effect, strong in bonding force and not easy to fall, and further, the three plates of the hub can be integrally connected tightly by aid of tight fit assembly. In addition, the hub has the advantages of high concentration precision, strong sealing property, simple assembly, attractive and novel appearance and the like.