Sampling of photoelectric imaging system could infinitely replicate the scene spectrum in spectrum space. If the sampling intervals were too large to satisfy the Nyquist criterion,the replicas would be overlapped and there was aliasing. The optical transfer function could demonstrate that how the optical imaging,integral sampling and reconstruction affected the overall performance. The optical transfer function was used for analysis of the photoelectric imaging system with OLPF. The results show that optic low-pass filter could effectively limit the scene spectrum width and critically satisfy Nyquist sampling condition,so the aliasing could be eliminated and quality of the image reconstructed is improved.