The deformation behavior and microstructure characteristics of Al-6.00Mg, Al-6.00Mg-0.10Zr and Al-6.00Mg-0.25Sc-0.10Zr (wt.%) alloys were investigated by hot compression tests and electron microscopy methods. The results show that after deforming under the maximum processing efficiency condition (673 K, 0.01 s^-1), dislocation densities of Al-6.00Mg, Al-6.00Mg-0.10Zr and Al-6.00Mg-0.25Sc-0.10Zr alloys are 2.68×10¹⁶, 8.93×10¹⁶ and 6.1×10¹⁷ m^-2, respectively. Their dynamic recrystallization fractions are 19.8%, 15.0% and 12.7%, respectively. Kernel average misorientation (KAM) analyses indicate that dislocation accumulation near grain boundaries is enhanced by adding Zr or Sc+Zr. Besides, the established hot processing maps, based on the dynamic material model (DMM), reveal that the addition of Zr or Sc+Zr can reduce the range of low-temperature unstable domain but expand the unstable domain at high temperatures and high strains. The experimental results further verify that under the testing deformation condition, only the Al-6.00Mg-0.25Sc-0.10Zr alloy cracks at 773 K and 1 s^-1.