CT devices and methods thereof are disclosed. The CT device comprises a circular electron beam emission array including a plurality of electron beam emission units that are distributed uniformly along a circle, wherein each electron beam emission unit emits electron beams that are substantially parallel to an axis of the circular electron beam emission array in sequence under the control of a control signal; a circular reflection target which is disposed to be coaxial with the circular electron beam emission array, wherein the electron beams bombard the circular reflection target to generate X-rays that intersect the axis of the circular electron beam emission array; and a circular detector array which is disposed to be coaxial with the circular reflection target and configured to include a plurality of detection units which receive the X-rays after they have passed through an object to be detected.