In order to process high-quality microstructures on the surface of titanium alloys and to investigate the influence of different factors on the surface quality, the nanosecond laser was used in the experimental research on the processing of titanium alloy Ti6Al4V. The surface morphology of titanium alloy workpieces processed under different parameters was measured by three-dimensional microscope and confocal microscope. Further, orthogonal experiments and one-way analysis of factors were used to investigate the effects of scanning speed, laser power and scanning line spacing on the processing morphology and roughness values. The results show that under the conditions of low power, high speed, and large line spacing, the material removal is discontinuous and the processed surface shows intermittent pit structure; with the increase of power, the decrease of processing speed and the reduction of line spacing, the material removal is gradually continuous and the processed surface quality is improved. The parameters of laser power 24 W, scanning speed 2000 mm/s, and line spacing 0.01 mm were selected to successfully process the array microgroove structure with a width of 500 μm and a depth of 140 μm on the surface of titanium alloy. This study has good practical value for laser processing of the surface microstructure of titanium alloys.