Abstract: Starting from the polarization matrix and propagation equation of the cross-spectral density matrix,a detailed study of the influence of hard-edge aperture on the spectral switch of polychromatic vector Gaussian-Schell model beams is performed.It is shown that before inserting a polarizer the transition height Δ of the spectral switch decreases,the minimum Smin and the critical position zc/z0 increase as the truncation parameter δ increases.After inserting the polarizer,the spectral switch varies with the truncation parameter δ in a similar way as the case without the polarizer.However,the polarization angle θ affects the range of the truncation parameter δ at which the spectral switch appears.