Industrial pure titanium TA2 due to its excellent corrosion resistance is widely used in the water environment,in the actual production,pure titanium is mostly welded by TIG welding,but slow welding speed leads to low efficiency. The subject of the 0.9 mm TA2 laser welding research,first has carried on the orthogonal experiment of four factors and five levels. These four factors are laser power,welding speed,defocusing and laser incident angle,it is found that laser power and welding speed have the greatest influence on forming;then each factor is analyzed by single factor analysis,found that increasing laser power or decreasing welding speed can suppress the undercut,increasing the amount of positive defocus can reduce the back spatter,forward laser incident is easier to achieve penetration than backward incident.