The invention relates to a core-shell structural organic/ inorganic composite hollow porous microsphere and a preparation method thereof. The method comprises the following steps: dissolving styrene,a bifunctionality dimethacrylate organic monomer, a photoinitiator and an organic UV absorbent into a solvent to obtain an electronic injection solution; adding modified titanium dioxide containing two bonds in the surface to the electronic injection solution to disperse uniformly; and performing electrostatic spraying in a visible light condition to obtain the hollow porous microsphere comprisinga crosslinking sphere, titanium dioxide particles and the organic UV absorbent; the crosslinking spheres are hollowed out, the surfaces are porous, and the crosslinking spheres are provided with crosslinking structures; the titanium dioxide particles are wrapped with the crosslinking spheres are in a covalent bond connection manner; the organic UV absorbent is doped in the crosslinking structuresand/ or attached to the inner walls of the crosslinking spheres. The method is simple and convenient in processes; the prepared hollow porous microspheres have the advantages of being good in extinction effect, high in UV resistance, high in smelting temperature, and high in thermal decomposition temperature.