A novel polymer microsphere with both UV-shielding and blue-light-emitting characteristics was fabricated by grafting disodium 4,4’-bis[(4-anilino-6-hydroxyethylamino-1,3,5-triazin-2-yl) amino] stilbene-2,2’-disulphonate (VBL) onto poly (maleic anhydride-co-α-methyl styrene) (PMAS) microspheres via esterification reaction. The as-prepared PMAS-VBL microspheres were then incorporated into polyvinyl alcohol (PVA) to prepare composite films. The introduction of PMAS-VBL endowed PVA with excellent UV-shielding and fluorescent properties, which mainly derived from UV-to-blue light converting ability of VBL. PVA films containing 7 wt% PMAS-VBL microspheres can block almost 100% UV light while the visible light transmittance was maintained at 66.9% and absolute quantum yield of the films reached up to 74.26%. This work opens up a new pathway for fabricating UV-filters and blue light converter, which are very promising for a diversity of UV-shielding and fluorescence-based applications.