Well-organized TiO₂ nanorod arrays (TNRs) have increasingly attracted our attention in recent years due to their excellent photocatalytic properties. However, it is of great importance to prepare more efficient photocatalysts using a facile method towards their more widespread use. In this work, K₆SiW₁₁O₃₉Co(II)(H₂O) (SiW₁₁Co) and Ag nanoparticles were introduced into TNRs using spin-coating and chemical bath deposition methods. It was found that TNRs/SiW₁₁Co/Ag composite films with an active area of only 1 cm² exhibit highly efficient and sustainable properties for the photodegradation of NO₂ and display a significant enhancement compared with P₂₅ and pure TNRs. Photocatalytic measurements demonstrated that both SiW₁₁Co and Ag synergistically improve the light absorption and charge separation efficiency, thus obtaining the most efficient photocatalytic performance. In addition, the probable photocatalytic mechanism and the dominating active species for NO₂ photodegradation were also proposed, in order to testify the effectively enhanced photocatalytic ability of the TNRs/SiW₁₁Co/Ag composite. Hence, the design of these polyoxometalate and metal particle co-modified TNRs may provide a new tactic for developing promising materials for photocatalytic degradation.