<p>As a critical optical material, K9 glass is widely used in modern optical technologies and precision manufacturing processes. To meet the growing demand for high-precision optical processing, it is essential to improve surface quality. In this study, a novel glass fiber-reinforced sol–gel polishing tool was proposed, which was prepared by combining sodium alginate with sodium carboxymethyl cellulose to form a binary composite system (SA-CMC), with glass fibers serving as the filler skeleton, resulting in a sol–gel polishing tool with excellent performance. The results indicate that a moderate increase in glass fiber content effectively inhibits shrinkage and deformation of sol–gel polishing tools, improving the forming effectiveness. Simultaneously, the increase in the content of the binary composite system improved the mechanical properties of the tool. Through formulation optimization, the use of 30 wt% F-doped CeO₂ polishing powder achieved a surface roughness of 0.49 nm alongside a material removal rate of 318.56 nm/min after 30 min of polishing. Additionally, a smooth surface with a roughness of 0.46 nm was achieved in the polishing of curved optical glass. The study of the material removal mechanism revealed that water molecules form Si–OH groups on the surface of the glass during polishing. The oxygen vacancies in CeO₂ easily adsorb water molecules and generate Ce-OH groups. Si–OH reacting with Ce-OH forms Si–O-Ce bonds. The breaking of these unstable bonds facilitates the removal of the material.</p>