A large amount of defects are created on the subsurface of fused silica optical elements after precision finishing, which can easily cause laser-induced damage, threatening the normal work of optical elements under an ultra-violet (351 nm/ 355 nm) laser. In the process of wet etching, the etching solution reacts with fused silica to passivate structural cracks, remove contaminative impurities in the subsurface layer, thus alleviate defects to a great extent and improve the damage resistance performance of elements. The damage mechanism of fused silica optical elements is analyzed, the technical processes of mineral acid leaching, hydrofluoric acid-based etching and other wet etching are introduced. The influence of etching parameters on the laser-induced damage threshold of elements is investigated. The present research status of this field is summarized and the future development trend is prospected.