<p>Compared with peroxidase, oxidase does not rely on H₂O₂ as a substrate, and usually has high selectivity towards substrates, catalyzing specific oxidation reactions. Fortunately, in the work, mono V-substituted phosphomolybdic acid H₄[PMo₁₁VO₄₀] (PMo₁₁V₁) was the first substance to be discovered with similar enzymatic activity and exhibited an extremely rapid reaction rat. Where the coexistence of Mo⁶⁺/Mo⁵⁺ and V⁵⁺/V⁴⁺ after the reaction implies that the transformation between elemental oxidation states dominates the reaction mechanism, rather than a unidirectional decrease. More specifically, high valent Mo and multi-valent V can catalyze the oxygen in water to generate O₂^<b>·</b>−, <b>·</b>OH, and H₂O₂, a cascade catalytic reaction, further catalyze H₂O₂ into <b>·</b>OH. With the reducibility of tannic acid (TA), a convenient, sensitive and effective colorimetric platform for TA detection was successful established, which shows good respond toward TA with a linear relationship in the range of 0-100 <i>µ</i>M and a low detection limit of 0.34 <i>µ</i>M. Also the application of the PMo₁₁V₁ sensor for TA detection in real tea was demonstrated and satisfactory results was obtained.</p> Graphical Abstract <p></p>