It is an effective approach to obtain high power laser output by spectral beam combining technology based on the sinc-apodized reflective volume Bragg grating. Considering the polarization of the monochromatic plane wave incident beam, the effects of the grating parameters on the diffraction efficiency, spectral selectivity and angular selectivity of the grating are analyzed by using the chain matrix method. The results show that the incident angle affects the diffraction efficiency greatly when the incident beams have different polarizations. The diffraction efficiency of the sinc-apodized reflective volume Bragg grating increases with the increase of the grating thickness and/or refractive index modulation, and it can be achieved higher than 99% with different polarizations at small incident angle when the product of the grating thickness and refractive index modulation is larger than 1.7028×10-6. The spectral selectivity and angular selectivity of the sinc-apodized reflective volume Bragg grating increase with the increase of the refractive index modulation, but decrease with the increase of the diffraction efficiency. By optimizing the grating parameters of the sinc-apodized reflective volume Bragg grating, the channel spectral separation lower than 200 pm can be achieved.