The invention discloses a dark filed imaging method based on a neutron grating interferometer. The dark filed imaging method is characterized by comprising the following steps: 1, moving a grating to fix the working point of the neutron grating interferometer in a peak position of a light intensity curve; 2, acquiring a projected image of background and a projected image of an imaged object respectively; 3, moving the grating to fix the working point of the neutron grating interferometer in a valley position of the light intensity curve; 4, acquiring a projected image of the background and a projected image of the imaged object respectively; 5, extracting a dark field signal of the imaged object. With adoption of the method, the dark field signal of the imaged object can be extracted accurately, and limitation that the dark field signal cannot be extracted accurately with a phase stepping method during low photon counting is overcome, so that a novel pathway is provided for accurate and quantitative characterization of the imaged object.