The Mg-Zn-Ca-Sr alloy has good application prospects as a bone implant material; however, the as-cast alloy has both poor plasticity and formability, and there are few studies on its deformation properties. In this study, the microstructure, deformation behavior, textural evolution, and processing map of an Mg-3wt%Zn-1wt%Ca-0.5wt%Sr alloy were studied via a compression test using a Gleeble 1500D thermo-mechanical simulator. The mean apparent activation energy of the hot compression deformation of the Mg-3wt%Zn-1wt%Ca-0.5wt%Sr alloy was 250.44 kJ/mol. With an increase in temperature, both the grain size and the degree of dynamic recrystallization increased. Dynamically recrystallized grains predominantly nucleated near the grain boundary and the secondary phases. After compression, the alloy had a strong basal texture, and its textural strength decreased at first and then increased slightly as the deformation temperature rose. The optimal process parameters of the as-cast Mg-Zn-Ca-Sr alloy involved deformation temperatures of 603-633 K and strain rates of 0.03-0.005 s(-1).