This study comparatively investigated the corrosion behavior of WE43 Mg alloy modified by stationary shoulder friction stir processing (SSFSP)+aging treatment and conventional T6 condition. Microstructure analysis revealed that the conventional T6 alloy ehixbited coarse grains (~120 μm) with chain-like block precipitates and dispersed nanoscale precipitates, while SSFSP (designated P-1) generated refined grains with randomly distributed precipitates and a nearly symmetric texture distribution from the advancing side to the retreating side. Subsequet aging treatment of the SSFSPed sample (designated PA-1) maintained fine grains and unchanged texture characteristics but introduced numerous precipitates at the grain boundaries and within the grains, significantly increasing hardness compared to P-1. The corrosion results showed a distinct performance trend: P-1>PA-1>T6. For T6, the coarse grains and chain-like distribution of large block precipitates made it highly susceptible to localized corrosion. In contrast, the fine grain structure and randomly distributed fine precipitates in P-1 effectively inhibited localized corrosion. While the PA-1 retained the fine grains, its discontinuous grain boundary precipitates promoted micro-galvanic corrosion effect between the precipitates and the adjacent matrix, thereby reducing its corrosion resistance compared to the P-1. Additionally, the SSFSP-modified matrix exhibited enahnced intrinsic corrosion resistance relative to the T6 sample. This improvement was attributed to the altered texture induced by SSFSP, which reduced the surface energy and increased the work function.