The hot compression behavior of as-extruded Mg-0.6Mn-0.5Al-0.5Zn-0.4Ca alloy was studied on a Gleeble-3500 thermal simulation machine. Experiments were conducted at temperatures ranging from 523 to 673 K and strain rates ranging from 0.001 to 1 s⁻¹. Results showed that an increase in the strain rate or a decrease in deformation temperature led to an increase in true stress. The constitutive equation and processing maps of the alloy were obtained and analyzed. The influence of deformation temperatures and strain rates on microstructural evolution and texture was studied with the assistance of electron backscatter diffraction (EBSD). The as-extruded alloy exhibited a bimodal structure that consisted of deformed coarse grains and fine equiaxed recrystallized structures (approximately 1.57 µm). The EBSD results of deformed alloy samples revealed that the recrystallization degree and average grain size increased as the deformation temperature increased. By contrast, dislocation density and texture intensity decreased. Compressive texture weakened with the increase in the deformation temperature at the strain rate of 0.01 s⁻¹. Most grains with {0001} planes tilted away from the compression direction (CD) gradually. In addition, when the strain rate decreased, the recrystallization degree and average grain size increased. Meanwhile, the dislocation density decreased. Texture appeared to be insensitive to the strain rate. These findings provide valuable insights into the hot compression behavior, microstructural evolution, and texture changes in the Mg-0.6Mn-0.5Al-0.5Zn-0.4Ca alloy, contributing to the understanding of its processing-microstructure-property relationships.