It is disclosed an imaging system comprising: radiation generating means including at least one radiation source for generating radiations; data acquiring means including an detector matrix faced the radiation source for obtaining projection data by receiving radiations penetrated through an object to be inspected; transporting means for making the object to be inspected between the radiation source and the detector matrix linearly moving relative to the radiation source and the detector matrix; and controlling and image processing means for controlling the radiation generating means, the data acquiring means and the transporting means, and for reconstructing an image of the object to be inspected from the projection data. The imaging system according to the present invention achieves a real stereoscopic radiography by using straight-line trajectory scan and reconstructing a tomographic or stereoscopic image through a straight-line filtered back-projection algorithm. The present imaging system has advantages of fast examination speed, no rotation, and out of large cone-angle problem in a circular-orbit cone-beam CT.