The ablation debris around the mitigated damage site on the surface of fused silica is one of the major factors inducing the damage of optics. The debris are classified into two types based on the ablation degree. The large-beam CO2 laser passivation and the buffered hydrofluoric acid solution etching method are used to eliminate the debris according to its types. Meanwhile, the corresponding optimal condition parameters are also obtained. The results show that the two methods can effectively eliminate the debris and improve the resistance damage capability of mitigated sites.