CT Devices and methods thereof are disclosed. The CT device comprises an electron beam generation unit, a circular reflection target (9) and a circular detector array. The electron beam generation unit comprises an electron gun (7), a deflection scanning unit and a restrictor (16), wherein the electron gun (7) generates electron beams, the deflection scanning unit deflects the electron beams with a deflection direction varying as time so as to implement a circular scanning, and the restrictor (16) has a plurality of circularly distributed holes, and wherein when the electron beams scan along the circularly distributed holes, a plurality of electron beams that are distributed circularly are output. The circular reflection target (9) is disposed to be coaxial with the circularly distributed electron beams, wherein the circularly distributed electron beams bombard the circular reflection target (9) to generate X-rays that intersect the axis of the circularly distributed electron beams. The circular detector array (11) is disposed to be coaxial with the circular reflection target and includes a plurality of detection units which receive the X-rays after they have passed through an object to be detected (10).