Based on interference effect at the airgap cementing layer of GlanTaylor prism and GlanFoucault prism, the effect of airgap polarizing prism on the transmitted light intensity distribution of single-mode Gaussian beam is analyzed. The result shows that, for certain wavelength and airgap thickness, the transmitted light intensity oscillates periodically with the change of incident angle, and for a certain incident angle, the transmitted light intensity oscillates periodically with the change of airgap thickness. The profile of transmitted Gaussian beam varies with the change of incident angle and airgap thickness. Considering the effect on light intensity and beam profile, GlanTaylor prism is more robust than GlanFoucault prism, indicating that the former has better general performance than the latter.