Abstract: Titanium alloys are widely used in armor protective structures because of superior specific strength and ballistic performance. During practical service, armor protective structures may be damaged by bullets, so it is important to study the armor-piercing damage of titanium alloys. The research status of the armor-piercing damage of titanium alloys was analyzed from the following four aspects:armor-piercing process, damage behavior, failure mechanism, and problems in these studies. The results show that the damage mode of armor of titanium alloys has something to do with the penetration mode and the microstructure. There is still some deficiency in the following research fields on the armor-piercing damage of titanium alloys:transmission characteristics of stress wave, quantitative characterization of damage area, characterization and evaluation of micro damage and typical microstructure, key factors and design optimization of bullet resistance. The analysis results provide some reference for the application of titanium alloys in armors.