In heterogeneous catalysis, uncovering the dynamic evolution of active sites in the working conditions is crucial to realizing increased activity and enhanced stability of catalyst in Fenton-like activation. Herein, we capture the dynamic changes in the unit cell of Co/La-SrTiO3catalyst during the exemplary peroxymonosulfate activation process using X-ray absorption spectroscopy and in situ Raman spectroscopy, revealing the substrate tuned its structural evolution, which is the reversible stretching vibration of O-Sr-O and Co/Ti-O bonds in different orientations. This process effectively promotes the generation of key SO5* intermediates, which is beneficial to the formation of1O2and SO4•−from persulfate on the Co active site. Density functional theory and X-ray absorption spectroscopy show that the optimized structural distortion enhanced the metal-oxygen bond strength by tuning theegorbitals and increased the number of transferred electrons to peroxymonosulfate by about 3-fold, achieving excellent efficiency and stability in removing organic pollutants.