The catastrophic optical damage of the high power laser is studied, and the damage mechanism of the laser facet coating is analyzed. In order to increase the output power of the laser, the TiO2 is used to replace the Si as the high refractive index materials, the nonstandard film is set up to reduce the intensity of electric field. Meanwhile, the roughness of the film materials is optimized, and the ion source is used to clean and flux. The threshold of the catastrophic optical damage is effectively improved. The results show that the proposed laser has a maximum continuous output power of 13.6 W.