The principles of pulse-front distortions production and its possible sources in a large-aperture short-pulse laser system are described. By using Fourier optics, a theoretical model based on single-pass compression is set up for the study of the pulse-front distortion. For the first time the effects of the pulse-front distortion on the spatial and temporal properties of the output pulse from the compressor is investigated. With the model we analyze all kinds of distortion sources, including the AOPDF, the lens and the wedges by numerical simulation for a large-aperture short-pulse system. The result shows that the pulse width in the near field broadens remarkably and the pulse-front shape of the output pulse differs from that of the input pulse except in the central part in the cross section whose area is determined by the bandwidth of the system.