Driven by the synergistic-directing effect of the lacunary fragments, [B-α-GeW9O34]10- and [B-α-GeW11O39]8-, an unprecedented hepta-Zr-substituted polyoxometalate (POM) assembly K2Na6H10(Hpy)3[SbZr7O6(OH)4(B-α-GeW9O34)2(B-α-GeW11O39)2]·28H2O (1) was made under hydrothermal condition and structurally characterized. Of which, a unique hepta-Zr cluster, [SbZr7O6(OH)4]15+ core, was built by two trilacunary [B-α-GeW9O34]10- fragments and two monolacunary [B-α-GeW11O39]8- fragments and further arranged in a mode of a vertical cross and formed a pseudo-tetrahedron geometry. Compound 1 features the first Zr7-cluster-substituted POM. Moreover, 1 is an effective heterogeneous catalyst for the catalytic oxidation of sulfides into the corresponding sulfones with H2O2, manifesting distinguished conversion, excellent yield, and desired recyclability.