The hot deformation behavior of Pt-10Ir alloy was studied under a wide range of deformation parameters. At a low deformation temperature (950-1150 °C), the softening mechanism is primarily dynamic recovery. In addition, dynamic recrystallization by progressive lattice rotation near grain boundaries (DRX by LRGBs) and microshear bands assisted dynamic recrystallization (MSBs assisted DRX) coordinate the deformation. However, it is difficult for the dynamic softening to offset the stain hardening due to a limited amount of DRXed grains. At a high deformation temperature (1250-1350 °C), three main DRX mechanisms associated with strain rates occur: DRX by LRGBs, DRX by a homogeneous increase in misorientation (HIM) and geometric DRX (GDRX). With increasing strain, DRX by LRGBs is enhanced gradually under high strain rates; the “pinch-off” effect is enhanced at low strain rates, which was conducive to the formation of a uniform and fine microstructure.