X-ray has been widely used in medical diagnosis and other fields with the non-destructive merit. Recently, the cold cathode X-ray source based on field emission, which are different from traditional hot cathode X-ray source, have overcome the limitations of traditional X-ray source due to their small size, addressable, and integrated characteristics, making CT imaging methods can be further developed. Especially X-ray sources using ZnO nanowires as cold cathodes can densely integrate a large number of X-ray sources into flat panel devices. When we use this flat X-ray source to light up multiple sources to scan an object at the same time, small source spacing will cause inevitable projection aliasing. Therefore, we propose an image restoration algorithm for projection aliasing, and use the method of projection rearrangement to remove projection aliasing. In addition, we estimated the spectrum of the flat-panel X-ray source by solving the spectral model parameters from the attenuation data of materials of different thicknesses, and used the spectral information to simulate the effect of the proposed image restoration method on the new photon counting detector. The results of simulation experiments show the effectiveness of this method and the potential of this new imaging mode.