In this paper, different cuprates of Mg-9Gd-4Y-2Zn-0.5Zr (wt.%) alloys were prepared using Conventional Backward Extrusion (CBE) and Rotational Backward Extrusion (RBE) processes. The corresponding regions of the different cuprates were characterized using OM, SEM, EBSD and other testing methods. The results show that the grain refining ability of RBE is much larger than that of CBE, and the grain refining effect in the heart of RBE is the best, and the content of Dynamic Recrystallization (DRX) in the RBE-III region can be up to 98.1%, with an average grain size of 2.5 μm. The texture weakening ability of RBE is also better than that of CBE, and the texture strength of the core can be weakened to 1.258. In the RBE cups, the degree of crushing of the LPSO phase is also larger than that of CBE, and the distribution of the second phase (β-phase) is more uniform, and the precipitated β-phase can promote DRX through the mechanism of Particles Simulated Nucleation (PSN) and restrain the growth of the grains through the pinning effect. In CBE and RBE cup molding processes, the dynamic recrystallization mechanism is the same, which is Continuous Dynamic Recrystallization (CDRX) and Discontinuous Dynamic Recrystallization (DDRX).