An X-ray imaging system using multiple pulsed X-ray sources in motion to perform high efficient and ultrafast 3D radiography is presented. There are multiple pulsed X-ray sources mounted on a structure in motion to form an array of sources. The multiple X-ray sources move simultaneously relative to an object on a pre-defined arc track at a constant speed as a group. Each individual X-ray source can also move rapidly around its static position in a small distance. When an X-ray source has a speed that is equal to group speed but with opposite moving direction, the X-ray source and X-ray flat panel detector are activated through an external exposure control unit so that source stay momentarily standstill. It results in much reduced source travel distance for each X-ray source. 3D scan can cover much wider sweep angle in much shorter time and image analysis can also be done in real-time.