Abstract: In order to solve the connection problem of Al₂O₃ ceramic lined pipe in petroleum pipeline, a special semiconductor laser light source was developed for ceramic laser welding. The technological parameters and beam requirements for ceramic laser welding were investigated experimentally. By means of single tube space beam combination, polarization beam combination, wavelength combination and Fresnel focusing system, a semiconductor laser ceramic welding system with uniform light distribution field was developed. The results show that, the output power of the polarization combination module is 384W, the beam combination efficiency is up to 96.62%. After wavelength combination, the output power can exceed 800W, and the output spot uniformity of focusing system is 93.85%. The system can be applied to ceramic welding in different occasions, and meet the requirements of Al₂O₃ ceramic laser welding with 2mm thickness.