The invention discloses a core-shell structure loaded tungsten composite catalyst, a preparation method and application thereof. Existing synthesis of the main rings of quinolone drugs mostly has the defects of long synthesis steps, tedious operation, large amount of three wastes, high cost, etc. Fe3O4 colloid and SiO2/Fe3O4 composite nanoparticles are prepared to prepare a magnetic separation core-shell loaded tungsten composite catalyst WO3/SiO2/Fe3O4 used for catalytic synthesis of quinolone compounds. The invention provides an efficient quinolone compound preparation method with magnetically separable and recyclable catalyst. The catalyst prepared by the method provided by the invention can be reutilized in preparation of quinolone compounds, still maintains the original activity and is free of inactivation phenomenon, not only greatly improves the production efficiency, but also reduces environmental pollution.