This paper describes the synthesis of a novel W₆O₁₉/amine-containing magnetic silica (W₆O₁₉/MS) nanocomposite as a powerful nanocatalyst for the synthesis of spirooxindole-pyrans. The W₆O₁₉/MS nanocomposite was synthesized via grafting of propylamine on Fe₃O₄@SiO₂ followed by treatment with hexatungstate polyoxometalate ([Bu₄N]₂[W₆O₁₉]). This nanocomposite was characterized using FT-IR, SEM, VSM, EDX, XRD and TG techniques. The FT-IR, TG and EDX analyses showed high thermal and chemical stability of the designed catalyst. The XRD, VSM and SEM analyses also showed, respectively, high magnetic properties and good spherical morphology of the catalyst. The W₆O₁₉/MS catalyst was successfully used in the synthesis of spirooxindole-pyrans and gave the desired products in good to high yield. In addition, the W₆O₁₉/MS nanocomposite could be recovered and reused seven times without any significant decrease in its activity.