The invention discloses CT (computed tomography) equipment and a usage method thereof. The CT equipment comprises an electron beam generating device, an annular reflection target and an annular detector array, wherein the electron beam generating device comprises an electron gun, deflection scanning devices and a current-limiting device the electron gun generates electron beams the deflection scanning devices deflect the electron beams, and the deflection directions are changed along with time to realize annular scanning the current-limiting device is provided with a plurality of holes arranged annularly when the electron beams carry out scanning along the holes arranged annularly, a plurality of electron beams distributed annularly are output the annular reflection target and the annularly-distributed electron beams are coaxially arranged the electron beams bombard the annular reflection target to generate X rays intersecting with the axes of the electron beams distributed annularly the annular detector array is coaxially arranged with the annular reflection target and comprises a plurality of detector units and the X rays enter the corresponding detector units after penetrating through a detected object.
