A magnetic resonance diffusion tensor imaging method and corresponding device. The method includes acquiring omnidirectionally sampled diffusion weighted images of a plurality of training samples; performing diffusion tensor model fitting and undersampling for the omnidirectionally sampled diffusion weighted images of each training sample to obtain an omnidirectionally sampled diffusion tensor image and an undersampled diffusion weighted image; training a deep learning network, with the omnidirectionally sampled diffusion tensor images of the plurality of training samples as training targets and the undersampled diffusion weighted images as training data; acquiring undersampled diffusion weighted images of a target object; and inputting the undersampled diffusion weighted images of target objects into the trained deep learning network to obtain the predicted omnidirectionally sampled diffusion tensor images of the target objects. Also, a fiber tracking method and corresponding device.