Abstract: Demand for optical element resistance of laser damage is higher and higher in the high power laser system. The damage characteristics and mechanism of film by pulse laser induced damage was researched. The experiments used by YAG pulsed laser for TiO2/SiO2 thin film were offered for 1-on-1 way of laser induced. The experimental results show that the impact on the optical transmittance of thin film is not big in low energy laser induced. Under the low energy laser induced, film surface structure defect is repaired. The surface structure tends to be complete, and becomes uniform and fine. Under pulsed laser induced TiO2/SiO2 thin film, when the laser energy order is smaller, the laser damage threshold of thin film increases with the increased energy, damage threshold maximum can increase 1 times. When the laser energy order is bigger, thin film damage threshold decreases with the increased energy order.