Compared with traditional imaging that uses the first-order correlation of light fields to realize the one-to-one correspondence between the object and image spaces, ghost imaging realizes the correspondence based on the second-order correlation of light fields and thereby obtains object’s image information. By introducing light field fluctuation modulation and computational reconstruction, ghost imaging not only has higher information acquisition efficiency, but also improves the flexibility of image information acquisition modes, thus having imaging capabilities that traditional imaging does not have. The further developments of ghost imaging in system optimization and technical applications bring new demands and challenges to ghost imaging theory. In this paper, the recent research progress of ghost imaging theory in Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences was introduced from three aspects: the physical nature, the image information acquisition theory and theoretical resolution. And the future theoretical research on ghost imaging was prospected.