Abstract: In order to reduce the generation of pores and cracks, the laser tailor welding tests of 3mm thick 06Cr19Ni10 austenitic stainless steel plate were carried out under big defocusing distance by changing laser power, welding speed and defocusing distance.The results show that the change of process parameters has great influence on weld morphology, sizes, and microstructure.With the increase of laser power, the laser penetration ability is enhanced, and the width of welding seam increases obviously.With the increase of defocusing distance, the spot diameter increases and the laser energy density decreases, and the welding performance decreases.With the increase of scanning speed, the laser line energy decreases, the width of all parts of the weld decreases, thus reducing the weld performance.When the laser power is 3800 W, the welding speed is 14 mm/s, and the defocusing amount is+25 mm, the weld has no obvious pore defects, and the welded joint with the best morphology and mechanical properties are obtained.