Hot compression testing was used to investigate the hot deformation behavior of 7475 aluminum alloy in a temperature range of 573-723 K and a strain rate range of 0.01-10 s−1. The hot workability was studied by means of constitutive analysis, three-dimensional processing maps, and microstructure characterizations using optical microscopy, electron back-scattered diffraction, and transmission electron microscopy. The results showed that the flow stress was increased with the increment of strain rates or the decrement of deformation temperature. Based on 3D processing, a temperature range of 623-673 K and a strain rate range of 0.01-0.1 s−1 were proposed to domain the process. Dynamic softening mechanisms were found to be associated with different contributions of dynamic recovery, dynamic recrystallization, and grain boundary sliding in various deformation conditions. These findings, along with the microstructure observation, suggested that the safe-deformation regimes with higher dissipation efficiency could be attributed to the continuous dynamic recrystallization and grain boundary sliding. The flow-instability regimes could be caused by the flow localizations and the adiabatic shear bands.