AbstractDespite the impressive progress in mesoporous materials over past decades, for those precursors having no well‐matched interactions with soft templates, there are still obstacles to be guided for mesoporous structure via soft‐template strategies. Here, a polyoxometalate‐assisted co‐assembly route is proposed for controllable construction of superstructured mesoporous materials by introducing polyoxometalates as bifunctional bridge units, which weakens the self‐nucleation tendency of the precursor through coordination interactions and simultaneously connects the template through the induced dipole–dipole interaction. By this strategy, a series of meso‐structured polymers, featuring highly open radial mesopores and dendritic pore walls composed of continuous interwoven nanosheets can be facilely obtained. Further carbonization gave rise to nitrogen‐doped hierarchical mesoporous carbon decorated uniformly with ultrafineγ‐Mo2N nanoparticles. Density functional theory proves that nitrogen‐doped carbon andγ‐Mo2N can strongly adsorb polyiodide ions, which effectively alleviate polyiodide dissolving in organic electrolytes. Thereby, as the cathode materials for sodium–iodine batteries, the I2‐loaded carbonaceous composite shows a high specific capacity (235 mA h g−1at 0.5 A g−1), excellent rate performance, and cycle stability. This work will open a new venue for controllable synthesis of new hierarchical mesoporous functional materials, and thus promote their applications toward diverse fields.