An imaging system, comprising: an X-ray emission device; and a detector for receiving a scattered ray scattered from an object under inspection when an X-ray emitted by the X-ray emission device hits the object; wherein the X-ray emission device comprises: a cylinder, characterized in that the X-ray emission device further comprises: a collimator to form sectorial ray beams at a plurality of positions in an axial direction of the cylinder; a multi-beam X-ray source disposed in the cylinder, the multi-beam X-ray source comprising a plurality of focal spots arranged in the axial direction of the cylinder, wherein each focal spot is configured to emit an X-ray; and the collimator being disposed in the cylinder, the collimator enabling the X-rays emitted by the plurality of focal spots to form said sectorial ray beams at said plurality of positions in the axial direction of the cylinder, wherein the cylinder has a pencil beam forming part arranged over an axial length of the cylinder corresponding to the plurality of positions, and wherein the sectorial ray beams form pencil beams through the pencil beam forming part when the cylinder rotates around a rotation axis. an X-ray emission device; and a detector for receiving a scattered ray scattered from an object under inspection when an X-ray emitted by the X-ray emission device hits the object; wherein the X-ray emission device comprises: a cylinder, characterized in that the X-ray emission device further comprises: a collimator to form sectorial ray beams at a plurality of positions in an axial direction of the cylinder; a multi-beam X-ray source disposed in the cylinder, the multi-beam X-ray source comprising a plurality of focal spots arranged in the axial direction of the cylinder, wherein each focal spot is configured to emit an X-ray; and the collimator being disposed in the cylinder, the collimator enabling the X-rays emitted by the plurality of focal spots to form said sectorial ray beams at said plurality of positions in the axial direction of the cylinder, wherein the cylinder has a pencil beam forming part arranged over an axial length of the cylinder corresponding to the plurality of positions, and wherein the sectorial ray beams form pencil beams through the pencil beam forming part when the cylinder rotates around a rotation axis. a cylinder, characterized in that the X-ray emission device further comprises: a collimator to form sectorial ray beams at a plurality of positions in an axial direction of the cylinder; a multi-beam X-ray source disposed in the cylinder, the multi-beam X-ray source comprising a plurality of focal spots arranged in the axial direction of the cylinder, wherein each focal spot is configured to emit an X-ray; and the collimator being disposed in the cylinder, the collimator enabling the X-rays emitted by the plurality of focal spots to form said sectorial ray beams at said plurality of positions in the axial direction of the cylinder, wherein the cylinder has a pencil beam forming part arranged over an axial length of the cylinder corresponding to the plurality of positions, and wherein the sectorial ray beams form pencil beams through the pencil beam forming part when the cylinder rotates around a rotation axis. a collimator to form sectorial ray beams at a plurality of positions in an axial direction of the cylinder; a multi-beam X-ray source disposed in the cylinder, the multi-beam X-ray source comprising a plurality of focal spots arranged in the axial direction of the cylinder, wherein each focal spot is configured to emit an X-ray; and the collimator being disposed in the cylinder, the collimator enabling the X-rays emitted by the plurality of focal spots to form said sectorial ray beams at said plurality of positions in the axial direction of the cylinder, wherein the cylinder has a pencil beam forming part arranged over an axial length of the cylinder corresponding to the plurality of positions, and wherein the sectorial ray beams form pencil beams through the pencil beam forming part when the cylinder rotates around a rotation axis.