Hollow silica nanospheres (HSNs) have been widely used as antireflection coatings. However, it is difficult to incorporate them into optical polymer matrices because of their larger size and agglomerations problem, making the haze and transparency worse. Herein, the sub-20 nm HSNs were firstly synthesized by a reverse microemulsion method and the scale-up preparation was successfully achieved in a rotating-packed-bed reactor. The prepared nanocomposites possess super-high transparency and almost unchanged haze.