The invention discloses a dynamic magnetic resonance imaging method, comprising the following steps: scanning the whole visual field by a radio frequency coil, sampling to obtain a first image signal, and rebuilding a first image according to the first image signal; sampling to obtain a second image signal and a third image signal, namely sampling to obtain the second image signal and the third image signal according to the sampling rate of the second image and the third image after lowering the sampling rate of the second image and the third image; constructing a target function about the second image and the third image according to the second image signal and the third image signal; optimizing and solving the target function about the second image and the third image; reconstructing the second image and the third image according to the solution; sampling to obtain a fourth image signal; according to the third image signal and the fourth image signal constructing the target function about the third image and the fourth image; optimizing and solving the target function about the third image and the fourth image; and reconstructing the third image and the fourth image according to the solution.