ing at imaging to weak signal in a complex system, our research team proposes a method called move contrast X-ray imaging, which takes the advantage of the time evolution of modulation of each moving component to incident light field in a complex system, to differentiate the components and image them separately. Accordingly, the mutual interference between components is eliminated and the sensitivity to weak signals is improved significantly. Experimental results of angiography with low agent dose, agent-free imaging of water refilling along microvessels in plant branch, and sensitive tracking to ion migration in a electrolytic cell demonstrate the practicability of move contrast X-ray imaging of weak signals in complex systems while traditional methods fail. The concept of move contrast imaging is applicable to all wavelength, and the proposed method may find extensive applications in imaging of infrared and visible light bands.