In this work, the slip and twinning behaviors of AZ31 alloy during dynamic compression along the extrusion direction (ED) were systematically investigated using quasi-in-situ electron backscatter diffraction (EBSD) technique. The results indicate that the peak stress increases progressively with cumulative strain, indicating a pronounced strain-hardening response during successive compression. Twins are initiated at a strain of 3%, and dominated by \(\left\{ {10\overline{1}2} \right\}\) tensile twins. The volume fraction of twins increases with increasing strain, leading to effective grain subdivision and the introduction of abundant twin boundaries, which significantly hinder dislocation motion and contribute to strain hardening. Detailed analysis demonstrates that parallel twin within a single grain is activated by the same variant, whereas mutually perpendicular twins are activated by distinct variants. The texture transition from extrusion radius direction (ERD) to ED during compression is attributed to lattice rotation caused by twin activities. Meanwhile, Schmid factor (SF) and grain reference orientation deviation (GROD) analyses indicate that the slip mechanism continuously participates in strain coordination during the deformation. In the low-strain stage, basal slip is dominant, and non-basal slip is gradually activated with increasing strain, which acts synergistically with twinning in some grains. The multi-mechanism synergy effectively alleviates the strain incompatibility between grains and accommodates the local strain concentration. Investigating the deformation mechanism of extruded magnesium alloys under complex loading provides a reference for subsequent microstructure design and performance optimization.
