Molecular O2 activation on metallic oxide‐based catalysts surfaces is pivotal for catalytic oxidation reactions but highly depends on the O2 activation pathways or mechanisms. Thus, comprehensively understanding the mechanism of efficient O2 activation is conducive to extending the fundamental principles for O2 activation theories and designing novel catalysts for catalytic oxidation reactions. In this study, it is declared that the interstitial atomic Bi (IA Bi) anchored in the lattice interstice of MnO2 (Bi/MnO2) is capable of triggering an alternative twofold O2 activation boosting the catalytic oxidation reactions at room temperature. Explicitly, the IA Bi facilely induces the local lattice distortion reconstructing the local charge landscape, thus weakening the O2 dissociation energy barrier by elongating the OO bond length. And, the charge‐alternating process engineered by the IA Bi drives the alternative twofold O2 activation of the adjacent lattice oxygen and adsorbs dangling oxygen assisted by the consecutive O2 replenishment. Conclusively, this study not only declares the role of IA Bi in driving the charge‐alternating process during the twofold O2 activation but also extends the fundamental principles toward O2 activation mechanisms for catalytic oxidation reactions via atomic makeup engineering.