The invention discloses an optical imaging system and an imaging method regulated based on a spatial coherence structure, including the steps of: building a 4f imaging system; detecting, by a first optical detector, the shape of the spectrum domain obstacle in the 4f imaging system; designing a spatial coherence structure of the incident beam based on the shape of the spectrum domain obstacle, so that all the modes of the incident beam can pass through the opening in the obstacle; and placing an object to be detected in the optical path and detecting, by the second optical detector, the optical imaging information of the object to be detected. According to the present invention, in the case where the frequency plane of the 4f optical imaging system is partially occluded, imaging without speckles is enabled, utilization of the systematic light is substantially improved, and the signal-to-noise ratio in imaging is improved.