In order to overcome the inability of scanning multi-spectral imaging to capture multi-spectral data in dynamic scenes, a single-exposure multispectral imaging method for moving targets was proposed based on phase modulation. This method combined associated imaging technology, compressed sensing technology and spectral imaging, introduced a spatial random phase modulator into the imaging light path, modulated and compressed the three-dimensional map information data of the moving target object, then used the two-dimensional aliasing signal obtained by the detector to reconstruct the three-dimensional map information to achieve a single exposure and simultaneously obtained the three-dimensional map information of the moving target. It had the advantages of high utilization rate of light energy, short imaging time, and simple system structure. The experimental results show that when the average electron number of a single frame of CCD detection signal increases from 200 e^- at intervals of 100 e^- to 1300 e^-, as the average rRMSE value of the electron number increases, the relative root mean square error of the reconstructed image decreases correspondingly, and the reconstruction improved image quality; when the stepper motor drives the target object to continuously move at a speed of 30 Hz, a multi-spectral reconstructed image of the moving object with better quality can be obtained; a spectrometer is used to test the spectral distribution curves of different spectrum bands in the target object, and the results obtained are basically consistent with the spectral distribution curves of the reconstructed image, which proves the effectiveness of the method. The research results provide a useful reference for the application of multi-spectral correlation imaging technology in UAV platforms, dynamic monitoring and other fields.