Abstract: The key to construct the hot-cell is to calculate the buildup factors of radiation-protection glasses. However, there are few reports about the calculation of the buildup factor of radiation-protection glasses. In this article, G-P approximation method coefficients of 5 radiation-protection glasses are calculated according to the chemical composition of radiation-protection glasses and data from ANSI/ANSI-6.4.3. Based on the computed results, buildup factors of these 5 glasses are studied, interpolated and compared with exposure buildup factors calculated by the equivalent thickness of lead for the energy of gamma-ray emitted by nuclides, such as ⁶⁰Co. The results show that the fitting functions of exposure buildup factors and penetration depth have a high relevancy R² for a specific energy, the method of equivalent thickness is only appropriate for thin glasses and special attention must be paid to the glass thickness and gamma-ray energy. The results can be used as reference for the construction and shielding performance assessment of the viewing window of the hot-cell.