When the size of nanomaterials reduces to the sub-1 nm scale, benefiting from size-induced mechanical flexibility and nearly 100% exposure of surface atoms, some new physical and chemical phenomena emerge, such as flexibility and polymer-like rheology. However, how to design and synthesize superflexible and high-performance hybrid sub-1 nm superstructures remains a great challenge. Herein, by incorporating four kinds of tungsten-based polyoxometallate (POM) clusters into the synthetic system of MoO₃ during the nucleation step, we successfully prepared four kinds of super-flexible hybrid sub-1 nm nanobelt superstructures (HSNSs). Molecular dynamics (MD) simulations demonstrated that POM clusters interacted with MoO₃ molecules and co-assembled into stable HSNSs, which could shrink, bend, curl and twist randomly in space and show super-flexible properties. These four kinds of MoO₃–POM HSNSs not only performed high photothermal conversion but also showed excellent catalytic activity in the oxidation of thioethers at room temperature. This work paves the way for synthesis and broader applications of super-flexible cluster-inorganic-materials-based HSNSs.