Boron nitride (BN) nanosheets incorporated silica antireflective (AR) coating was successfully prepared on fused silica substrate to improve the antilaser-damage ability of transmissive optics used in high-power laser systems. The BN nanosheets were obtained by urea assisted solid exfoliation, and then incorporated into basic-catalyzed silica sols without any further treatment. The transmission electron microscope (TEM) images indicated that the BN nanosheets generally consisted of 2–10 layers. The antireflective BN/$\text｛SiO｝_｛2｝$ coating exhibited excellent transmittance as high as 99.89% at 351 nm wavelength on fused silica substrate. The thermal conductivity $0.135~\text｛W｝\cdot \text｛m｝^｛-1｝\cdot \text｛K｝^｛-1｝$ of the BN/$\text｛SiO｝_｛2｝$ coating with 10% BN addition was about 23% higher than $0.11~\text｛W｝\cdot \text｛m｝^｛-1｝\cdot \text｛K｝^｛-1｝$ of the pure $\text｛SiO｝_｛2｝$ AR coating. The laser-induced damage threshold (LIDT) of that BN/$\text｛SiO｝_｛2｝$ coating is also 23.1% higher than that of pure $\text｛SiO｝_｛2｝$ AR coating. This research provides a potential application of BN/$\text｛SiO｝_｛2｝$ coatings in high-power laser systems.