When a planar optical wavefront is made to propagate through a supersonic turbulent boundary, affected by the density fluctuation, its propagation direction and phase will change, which make target image blur, shifting, jitter et al and bring problems for target identification. By using the BOS-based Wavefront Sensing(BOS-WS) technique based on the principle of Background Oriented Schlieren(BOS), the optical wavefront propagated through a Ma=3.0 supersonic turbulent boundary layer was acquired. Based on the wave optics principles, the corresponding Point Spread Function(PSF) distribution and degraded image were computed. The research results show that many changes are found on the PSF peak value, peak value location and shape. The PSF peak value deceases largely, the PSF value peak position appears a significant move, the PSF shape appears multi peaks phenomenon, the spatial randomness of turbulent boundary layer density distribution is obtained, the image appears to a certain degree degradation after the PSF processing.