The invention discloses hollow glass beads and a preparation method thereof. The hollow glass beads are characterized by comprising chemical components in percentage by mass as follows: 45%-70% of SiO2, 15%-20% of Al2O3, 5%-10% of Na2O, 5%-10% of K2O, 0.5%-5% of Li2O, 0.5%-1% of CaO, 0.5%-1% of MgO, 0.01%-0.2% of S, 1%-2% of Fe2O3, 0.5%-2% of NaNO2, 0.02%-0.05% of ZrO2 and 0.02%-0.05% of TiO2. The hollow glass beads have the density of 0.1-0.5 g/cm<3>, the compressive strength up to 90-150 MPa and the particle size of 2-70 mu m. The hollow glass beads have the characteristics of light weight, large size, low thermal conductive coefficient, high compressive strength and good liquidity, cannot be broken easily, can be widely applied to raw materials of core materials for plastic and rubber, paint coatings, drilling fluids, marine chemistry, marine engineering, marine equipment and shipbuilding, and can be applied to deep sea oil drilling and production of light cores of ships, deep sea oil delivery pipelines and bathyscaphs.