Exploring efficient heterogeneous catalysts for catalytic oxidation of chemical warfare agents (CWAs) is highly desired. As a class of discrete anionic metal oxide clusters, polyoxometalates (POMs) provide abundant catalytic active sites, thus resulting their rich redox properties. Here, a family of known POM‐incorporated CuI‐resorcin[4]arene metal‐organic complexes, namely, [Cu4(TPTR4A)2][PW12O40](OH) ⋅ 0.5DMA ⋅ 5H2O (Cu‐PW), [Cu4(TPTR4 A)2][PMo12O40](OH) ⋅ 2DMA ⋅ H2O (Cu‐PMo) and [Cu4(TPTR4A)2][SiW12O40] ⋅ 2.5DMA (Cu‐SiW) were utilized as catalysts to promote the oxidation of 2‐chloroethyl ethyl sulfide (CEES). Strikingly, compared to the novel compound [Cu3Cl6(TPTR4A)(DMA)] ⋅ CH3CH2OH (defined as Cu‐T), the three complexes exhibited excellent stability, indicating that the integration of POMs and metal–organic units could improve the stability of the compounds. Moreover, Cu‐PMo and Cu‐PW showed higher activities for the catalytic oxidation of CEES to CEESO with selectivities both of 99 %. [ABSTRACT FROM AUTHOR]