<p>The appealing aesthetic characteristics and distinctive physiochemical properties have driven the continuous pursuit of assembling hollow crystalline cage molecules (CCMs). Herein, we present the first inorganic {Co₁₂}-added polyoxometalate cage Cs₈₅Na₂₀H₁₉₅[{SiW₁₀Co₂O₃₉}₄{SiW₁₀Co₂O₃₆}₂]·85H₂O (<b>1</b>), of which the polyoxoanion is assembled by 4 Keggin-type {SiW₁₀Co₂O₃₉} units and 2 {SiW₁₀Co₂O₃₆} units as the Vertexes and 12 W(Co)–O–W(Co) bonds as the linkers, resulting in a novel hollow cage with octahedral configuration. Intriguingly, the arrangement of 12 Co²⁺ and 12 W⁶⁺ centers within the central [Co₁₂W₁₂O₃₆]²⁴⁺ cage follows a truncated octahedral Archimedean-type tetrakaidecahedron, which resembles the <i>β</i> cage in zeolite structures. Furthermore, <b>1</b> displayed an efficient catalytic performance and satisfactory recyclability in the Knoevenagel condensation with the various benzaldehyde derivatives and malononitrile as substrates.</p>