An X-ray imaging system using multiple pulsed X-ray source pairs in-motion to perform highly efficient and ultrafast 3D radiography is presented. The sources move simultaneously on arc trajectory at a constant speed as a group. Each individual source also moves rapidly around its static position in a small distance, but one moves in opposite direction to the other to cancel out linear momentum. Trajectory can also be arranged at a ring structure horizontally. In X-ray source pairs each moves in opposite angular direction to another to cancel out angular momentum. When an individual X-ray source has a speed that equals to group speed but an opposite linear or angular direction, the individual X-ray source is triggered through an external exposure control unit. This allows the source to stay relatively standstill during activation. 3D data can be acquired with wider view in shorter time and image analysis is real-time.