A CT apparatus without a gantry. The CT apparatus includes a scanning passage; a stationary X-ray source arranged around the scanning passage and including a plurality of ray emission focal spots; and a plurality of stationary detector modules arranged around the scanning passage and disposed opposite the X-ray source. At least some of the plurality of detector modules may be arranged substantially in an L shape, a semicircular shape, a U shape, an arc shape, a parabolic shape, or a curve shape when viewed in a plane intersecting the scanning passage. The invention ensures that the stationary gantry type CT system has a small size, and a high data identification accuracy.