The invention discloses an ultra-fast single-excitation four-point Dixon water-fat separation imaging method. Single-excitation water-fat separation sequences and data processing modes of multiple versions are adopted, and the method is mainly used for enhancing the signal to noise ratio and increasing the scanning speed to obtain a same-phase diagram, a reverse-phase diagram, a water image and a fat image in which the field asymmetry effect is eliminated and obtain a field distribution diagram delta B0 and a precise distribution diagram (please see the formula in the description). Fast scanning is guaranteed, and meanwhile the clinical diagnosis needs of infants and restless patients are met.