<p>The phenomenon of variant selection in titanium alloys needs to be avoided as it has a negative impact on mechanical properties. In this study, a new method of aging treatment using pulse current coupled hydrogen is proposed to inhibit variant selection of cast Ti-6Al-4V alloy. The inverse pole figures and pole figures of cast Ti-6Al-4V alloy before and after aging treatment, as well as the distribution and area fraction of 12 varieties, are investigated using the quasi-in situ electron backscattered diffraction. The experimental results indicate that the aging treatment using pulse current coupled hydrogen can significantly inhibit the variant selection of the cast Ti-6Al-4V alloy, thereby refining the microstructure and improving the hardness of the cast Ti-6Al-4V alloy. Furthermore, the results of isothermal heat treatment demonstrate that the nonthermal effect of pulse current plays a crucial role in suppressing the variant selection in cast Ti-6Al-4V alloy. The interaction between atoms and drift electrons generated by the pulse current, especially at defect positions, increases the vibration of atoms and weakens the bonding strength between atoms. On this basis, the nonlinear response of the elastic-viscous system was described using the Maxwell model to elucidate the effect of pulse current on alloy system. This study provides additional driving force and a new mechanism for the generation of new variants during the aging period.</p> Graphical abstract <p></p>