Fused silica glass is non-crystalline material, the traditional detection methods have complicated steps and low measurement accuracy, residual stresses are often unable to direct quantitative detection. A new residual stress calculation method for fused silica polishing surface was proposed based on brittle solid fracture mechanics, in which a series of nano-indentation experiments were conducted by a sharp indenter, and the sensitive parameters were extracted during indentation process, the experimental data were linear fit and the line slopes were determined, so residual stress was often calculated indirectly by measuring the other physical parameters change caused by residual stress. Comparative analysis showed that the calculation results had in good consistency with the test results obtained by stress birefringence analyzer, so the correctness of the residual stress calculation method was verified.