<p>Anderson-type polyoxometalates (POMs) are widely regarded as ideal building blocks for constructing metal-oxo cluster-based Covalent organic frameworks (COFs) owing to the unique planar hexagonal structure. Different transition metals (TMs) can obviously regulate the structures and electronic properties of POMs. Then first-row TM embedded typical structure unit (TMMo₆C₈H₁₆N₂O₁₈) of POMs as a research object have been investigated by using density functional theory (DFT) calculations. The VMo₆C₈H₁₆N₂O₁₈ display the highest structural stability. The FeMo₆C₈H₁₆N₂O₁₈ exhibit the highest chemical activity. However, the CuMo₆C₈H₁₆N₂O₁₈ displays the largest dipole moment. The Fe in FeMo₆C₈H₁₆N₂O₁₈ exhibits the most Mülliken charge. Our findings maybe will provide a theoretical basis for the rational design of high-performance metal cluster-based POMs materials.</p>