Low dispersion mirrors with broad bandwidth and high damage threshold are indispensable optical components in a petawatt (PW) laser system. Here, we systematically investigate the optical properties, dispersion characteristics, damage resistance characteristics and damage mechanisms of metal-dielectric mirrors, dielectric mirrors and ternary composite mirrors. The dielectric films can improve the damage thresholds of metal films. The transmission efficiency and damage threshold of silver-dielectric mirrors are higher than those of Au and Al. The typical damage morphology of near threshold metal-dielectric mirrors under the action of femtosecond lasers is bulge, and the reason is that the metal layer absorbs a lot of energy and causes the thermal stress damage. In ternary composite mirrors, the existence of the protective HfO2 layers makes the electric field in Ta2O5 decrease, the initial damage layer is transferred to HfO2, and the threshold increases without sacrificing reflection bandwidth and dispersion performance.