Abstract: The application of high-repetition-rate, high-energy solid-state lasers places higher demands on the optical, mechanical, and thermodynamic properties of the gain medium, as well as on its compatibility with the saturation fluence. Garnet laser ceramics have the characteristics of high theoretical optical quality, short preparation cycle, high thermal conductivity, the ability to achieve high-concentration and uniform doping of active ions, and ease of fabricating composite structures. They are a promising gain medium material with great application potential. Neodymium doped lutetium aluminum garnet (Nd:LuAG) transparent ceramics have shown significant potential due to their outstanding optical, mechanical, and thermodynamic properties. In this study, commercially available Lu₂O₃, α-Al₂O₃, and Nd₂O₃ powders were used as experimental raw materials. Tetraethoxysilane (TEOS) and CaO were employed as sintering aids. Nd:LuAG transparent ceramics with a 1% neodymium atomic fraction and varying TEOS addition amounts were prepared via vacuum pre-sintering (1825 ℃, 5 h) combined with hot isostatic pressing (HIP) (1750 ℃, 3 h, 200 MPa). After HIP treatment, the Nd:LuAG transparent ceramics exhibited an average grain size of 15.2 μm, and their linear transmittance at 1064 nm showed a trend of first increasing and then decreasing with increasing TEOS content. When TEOS was added at a mass fraction of 0.6% and CaO at a mass fraction of 0.05%, the linear transmittance of the Nd:LuAG transparent ceramics at 1064 nm was 83.6%. The successful preparation of high-optical-quality Nd:LuAG transparent ceramics is of great significance for enhancing the performance of high-repetition-rate nanosecond high-energy solid-state lasers.