A vehicle-mounted inspection system for scanning an object under inspection in a scanning state and for traveling in a transport state, the system comprising: a chassis; a rotation mechanism disposed on the chassis; a first x-ray emission device connected to the rotation mechanism and configured to emit an x-ray from one side of an object under inspection towards the other side of the object under inspection; a first detection device connected to the rotation mechanism and configured to receive the x-ray emitted by the first x-ray emission device; wherein the system further comprises a second x-ray emission device connected to the rotation mechanism and configured to emit an x-ray from above downwards; and an elevating mechanism connected to the rotation mechanism and configured to lift up and down the second x-ray emission device, wherein: the rotation mechanism is configured to rotate the first x-ray emission device, the first detection device and the second x-ray emission device substantially around an upright axis between a retracted position in the transport state and an operating position in the scanning state, the second x-ray emission device comprises a second x-ray source arm and a second x-ray source disposed to the second x-ray source arm, and the elevating mechanism is adapted to elevate the second x-ray source arm and the rotation mechanism is adapted to rotate the second x-ray source arm such that the second x-ray source arm enters the scanning state. a chassis; a rotation mechanism disposed on the chassis; a first x-ray emission device connected to the rotation mechanism and configured to emit an x-ray from one side of an object under inspection towards the other side of the object under inspection; a first detection device connected to the rotation mechanism and configured to receive the x-ray emitted by the first x-ray emission device; wherein the system further comprises a second x-ray emission device connected to the rotation mechanism and configured to emit an x-ray from above downwards; and an elevating mechanism connected to the rotation mechanism and configured to lift up and down the second x-ray emission device, wherein: the rotation mechanism is configured to rotate the first x-ray emission device, the first detection device and the second x-ray emission device substantially around an upright axis between a retracted position in the transport state and an operating position in the scanning state, the second x-ray emission device comprises a second x-ray source arm and a second x-ray source disposed to the second x-ray source arm, and the elevating mechanism is adapted to elevate the second x-ray source arm and the rotation mechanism is adapted to rotate the second x-ray source arm such that the second x-ray source arm enters the scanning state. the rotation mechanism is configured to rotate the first x-ray emission device, the first detection device and the second x-ray emission device substantially around an upright axis between a retracted position in the transport state and an operating position in the scanning state, the second x-ray emission device comprises a second x-ray source arm and a second x-ray source disposed to the second x-ray source arm, and the elevating mechanism is adapted to elevate the second x-ray source arm and the rotation mechanism is adapted to rotate the second x-ray source arm such that the second x-ray source arm enters the scanning state.