Abstract: The thermal compression test for high-strength weldable Al-Zn-Mg-Zr alloy containing Sc was carried on Gleeble-1500 thermal simulator, the flow stress of the alloy during thermal deformation was studied, and the processing map of the tested alloy was established based on dynamic material model and PRASAD instability criterion and the optimal thermal working process parameters of the alloy was obtained.. The results show that the characteristic of high-temperature flow stress-strain curve of the tested alloy were mainly softening mechanism of dynamic recovery and dynamic recrystallization, the flow behavior could be described by a constitutive equation in hyperbolic sine function, and the deformation activation energy was 150.25 kJ·mol-1. The suitable thermal working process of the alloy was as follow: the deformation temperature was 360-400 ℃ and the strain rate was 0.001-0.003 s-1.