In this article, a systematic investigation into the corrosion and discharge behaviors of as‐rolled a represents aluminum, Z represents zinc, 9 and 1 represent their respective contents of 9% and 1% in the alloy (AZ91) magnesium alloy after electro pulsing treatment (EPT), considering rolling deformations of 0% (as‐cast AZ91 magnesium alloy), 20%, 30%, and 40%, is presented. In this investigation, immersion weight loss tests, electrochemical tests, and other experimental methods are employed. In the results, it is revealed that the content of the β‐Mg17Al12 phase gradually decreases with increasing rolling deformation after EPT. Notably, the highest content of β‐Mg17Al12 phase and the most outstanding corrosion resistance are achieved with as‐cast AZ91 magnesium alloy. Furthermore, at low current densities (5 and 10 mA cm−2), the 30% rolling deformation exhibits superior discharge activity, while the discharge activity of the 40% rolling deformation is most excellent at high current densities (40 and 50 mA cm−2). The microstructure observations support these findings, highlighting the close relationship between the corrosion resistance and discharge activity of as‐rolled AZ91 magnesium alloy after EPT, and the content of the β‐Mg17Al12 phase and the area of high‐energy grain boundaries.