<p>Titanium alloy is often used in a variety of complex curved parts in the aerospace field due to its excellent material properties. The traditional ball-end milling method is still the main means for processing titanium. Due to the difficult machining properties of titanium alloy materials, there will be serious tool wear and surface adhesion defects in the cutting process, and the change of tool posture will have a comprehensive impact on the above two problems. Therefore, this paper puts forward a tool feed direction optimization strategy considering tool wear and surface adhesion. First of all, based on the tool-workpiece contact geometrical relationship, the ball-end tool calculation model of the tool cutting edge element effective cutting length per-tooth cutting process is established. The axial position angle range of the cutting edge element actually participating in the cutting is determined. Then, through the experiment of milling titanium alloy with 25° oblique plane, the influence mechanism of feed direction on milling force, chip morphology, and surface morphology is analyzed, and the feed direction angle interval with relatively wear resistance and excellent surface quality is obtained. Finally, the tool wear experiments of symmetrical surfaces in various feed directions are carried out. The tool is worn slowly in the selected feed direction of the relative wear-resistant range, and better surface quality can be obtained. The average tool life in the optimized feed direction is 39.32% longer than that in the non-optimized feed direction. This study can provide a theoretical basis for tool path planning and tool posture selection in NC machining of titanium alloy complex surfaces.</p>