<p>To elucidate the origin of mechanical anisotropy in cylindrical Mg alloy components containing long-periodic stacking-ordered (LPSO) phases and to provide guidance for component-level microstructure design, this study systematically investigated the combined effects of texture and oriented LPSO phases on the three-dimensional mechanical anisotropy of a cylindrical Mg-Gd-Y-Zn-Zr components fabricated by back-extrusion. The results of uniaxial tensile tests show that there are significant differences in three-dimensional mechanical properties of cylindrical components, and the plastic anisotropy is more significant compared to the strength anisotropy. By comparing Schmid factor (SF) distribution and slip mode of primary-texture and secondary-texture, it is revealed that primary-texture grains have a greater influence on strength anisotropy than secondary-texture grains. The larger SF difference between primary-texture grains and secondary-texture grains leads to significant gradient slip, uncoordinated strain and dislocation accumulation, which results in stronger dislocation strengthening, strain strengthening, and strength anisotropy. The fracture of blocky LPSO phases leads to straight cleavage planes, and the matrix is prone to the formation of numerous tearing ridges. The oriented blocky LPSO phase affects the strength anisotropy through load-bearing strengthening effect, and affects the plastic anisotropy by changing microcrack propagation mode and fracture mechanism. Overall, the oriented blocky LPSO phase has a more significant effect on mechanical anisotropy than the texture.</p>