Noteworthy ductility Mg-8Gd-4Y-1Nd-0.5Si (wt.%) alloy with a strong non-basal texture was developed by 12 passes ofmulti-directional forging (MDF) combine with extrusion. The slip trace analysis indicated that deformation mechanism after3 passes of MDF and extrusion were basal < a > , pyramidal < a > and pyramidal < c + a > slips. The intensity of non-basaltexture increased from 5.37 to 8.03 with the MDF passes increased from 3 to 12, which means grain orientation tends tobe more consistent and makes the basal < a > slips easy to pass through grain boundaries to accommodate ductility. Withmore basal < a > slips crossing the grain boundaries, dislocation interaction in grain interior caused stress accumulation,exceeding the critical shear stress (CRSS) of slips with low schmidt factor (SF), and multiple slips appeared. The activationof slip cross grain boundary and multiple slip improved the elongation from 14.7% to 25.6% of MDFs-extruded Mg-8Gd-4Y-1Nd-0.5Si alloy.