Aim at the urgent requirements of alumina-based continuous ceramic fibers,boron-containing alumina-based continuous fibers were prepared through a sol-gel combined dry spinning technique.The effect of the content of spinning additive on the spinnability of the sol and the evolution of the phase composition and microstructure of the fibers during the ceramization were investigated.The results indicate that the gel fibers is lengthen up to 1.8 km with the PVA content of 1.5%.After ceramization, the ceramic fibers with the uniform diameter of 12 to 14 μm can be formed.The fibers obtained at 1 000 ℃ are composed of the crystalline γ-Al₂O₃ and amorphous phase.These fibers exhibit high tensile strength and modulus up to 2.0 GPa and 149 GPa, respectively.After calcined at 1 100 ℃ for 1 h,the fiber still can retain the 93% of original tensile strength. The as-prepared fibers show great potential in the area of aerospace and advanced manufacturing industry.