Spodoptera exigua nuclear polyhedral virus (SeNPV) is a kind of environmental-friendly biological pesticide with low drug resistance. However, SeNPV is inactivated easily under high ultraviolet (UV) and high temperature. In this paper, sodium alginate(SA) microbeads were prepared by atomization solidification method for embedding SeNPV, and functionalized modified by polydopamine(PDA)-coated. Furthermore, the composite microbeads were characterized by FTIR, DSC, TGA, SEM and particle size and distribution. The results showed that the D50 of the prepared PDA/SA-NPV (P/S-N) microbead was 132 μm, the stability of microbead structure at high temperature was good. The insecticidal activity of the compound microbead was higher than SeNPV suspension after UV treatment, which indicated the anti-ultraviolet property of the virus was enhanced under the double protection of calcium alginate and polydopamine.