A half of covering angle processing method is proposed for optimizing process efficiency and quality with ball-end tool axis tilt. Firstly, according to the features of ball-end tool structural, this paper introduced traditional no-tilt processing problems, such as tool fast wear and poor processing quality, and then verified the effect of tool tilt processing by analyzing and comparing cutting quality with the differences of the no-tilt processing and tilt processing. Finally, it introduced two optimization methods about tool tilt processing, and also made a comparison with its feature. The results show that traditional processing brings about more extrusion and scratches, while little and high efficiency with method of tool tilt processing. Conclusion: it not only brings higher processing quality and efficiency, but also can make the ball-end cutter be longevity of service.