The invention discloses a hollow glass brick and a preparation process thereof. The hollow glass brick comprises an upper glass block and a lower glass block and is characterized in that the upper glass block and the lower glass block are both hollow bodies, the center of each of the upper glass block and the lower glass block is provided with a through hole which is used for insertion of a rod member, the front and back plates of the lower glass block are arc-shaped, the corresponding upper glass block is arc-shaped, and the upper glass block and the lower glass block are bonded through a strong binder so as to form the hollow glass brick. The hollow glass brick and the preparation process have the following beneficial effects in usage: 1, the through holes are perforated in the hollow glass brick and can be connected through the rod member, so an ornament obtained through superimposition of the hollow glass brick is firmer; 2, the advantages of high efficiency, small workload and low cost are obtained during processing of the hollow glass brick; and 3, the surface of the red-core glass brick is more beautiful and glittering.