Active double bonds were introduced onto the surface of silica (SiO2) through organic modification，and the surface functionalized silica (FSiO2) was successfully introduced into UV light-cured polyurethane acrylate (PUA) prepolymer. Fourier Transform infrared spectroscopy (FTIR)，X-ray photoelectron spectroscopy (XPS)，Thermogravimetric Analysis (TGA)，X-ray diffraction (XRD) and Rotary rheometer were used to characterize and test SiO2，FSiO2 and PUA/FSiO2 composite, with the stability of SiO2 and FSiO2 in dimethyl formamide (DMF) studied as well. The results showed that organic chain segments were successfully connected to the surface of OCMSs and the grafting rate was as high as 10.1%. Compared with SiO2，FSiO2 after organic modification had better dispersion in DMF. Besides，FSiO2 was conducive to improving the heat resistance, gel rate and water contact angle of PUA coatings to certain extent, and it also helped to increase the pencil hardness of the coatings.