At present, the roughness of the laser welding line of the dewar package of the infrared detector is large. The strength and internal vacuum of the dewar welding line during the long-term use of the detector components are not good, which affects the life and performance of the detector. In order to solve these problems, it is proposed to apply laser polishing technology to the polishing treatment of laser welding line of dewar components. The experiment investigated the influence of main parameters on the polishing quality, and the laser polishing results were tested using the laser confocal microscope. The results show that the laser polishing technology can reduce the surface roughness Ra of the laser welding line from 0.25 mm to 0.03 mm. This fully proves that the use of green, efficient, non-contact laser polishing can achieve high-quality polishing of the laser welding line of the outer surface of the infrared detector dewar components, which has great potential application value in the field of infrared detector manufacturing.