Subsurface damage would be inevitably formed during grinding of brittle material. The characterization and removal of the subsurface damage remains the main concern to acquire the high laser-induced damage threshold fused silica optics. Several subsurface damage characterization techniques are revieved, in which the feasibility of etching and surface peak-to-valley (PV) roughness method is revaluated experimentally and the error is also analyzed. Herein a new subsurface damage characterization using HF etching and polishing layer by layer is proposed. Then, these subsurface damage characterization techniques are compared in applying to ground fused silica samples. And a good concordance between different measurements is found.