Using the entangled two-photon systems, we experimentally demonstrate the predictions of the analog Clauser-Horne- Shimony-Holt (CHSH) inequality and investigate the robustness of the CHSH-class inequality in the bit-flip noisy environment. We obtain the experimental results of CHSH inequality and analog CHSH inequality as SCHSH=2.64±0.02 and SanalogCHSH=2.76±0.02, respectively, and prove that the analog CHSH inequality is more robust against bit-flip noise than the CHSH inequality. It provides better advantages for the experimental study and application.