The invention discloses a high-strength aluminum alloy plate preparation process and an aluminum alloy plate, and relates to the field of aluminum alloy plates, the preparation process comprises alloy preparation, ultrasonic treatment, casting extrusion molding, primary aging treatment, rolling into a plate, solid solution quenching and secondary aging treatment; the aluminum alloy plate is made of an Al-Zn-Mg-Cu series alloy, and is specifically made of the following metals in percentage by mass: 4.5 to 5.2 percent of Zn, 1.2 to 2.0 percent of Mg, 1.0 to 1.8 percent of Cu, 0.02 to 0.06 percent of Ni, 0.05 to 0.15 percent of Ti, 0.01 to 0.02 percent of Y, 0.02 to 0.05 percent of Zr and the balance of Al. The method has the beneficial effects that the semi-solid forming and casting-extruding integrated forming technology is adopted, the grain size in the aluminum alloy is effectively reduced in the metal forming step, meanwhile, multi-time multi-stage aging treatment is adopted, deformation stress generated in the rolling process of the alloy is fully eliminated, recrystallization in the alloy is promoted, and therefore the service life of the aluminum alloy is prolonged. And the grain size in the aluminum alloy is improved, the plasticity of the aluminum alloy is effectively improved, and the punch forming performance of the alloy is improved.