The close-packed hexagonal structure pure magnesium has few independent slip systems which result in poor plasticity. In the present paper, the pure magnesium was deformed by equal channel angular pressing (ECAP). Results show that due to grain refinement and weakening of base texture, plasticity of pure magnesium is significantly improved. The strength of pure magnesium decreases after ECAP deformation mainly because the influence of base texture weakening is greater than that of grain refinement. Moreover, the corrosion resistance of pure magnesium is significantly enhanced after shear stress deformation because of the increase of self-corrosion potential and corrosion current density. The corrosion mechanism of pure magnesium may change from local corrosion to uniform corrosion, which can reduce the corrosion falling and ensure the integrity of samples during immersion in the standard simulated body fluid.