This paper focuses on the new connotation and application of point spread function （PSF）of optical imaging in computational imaging. Firstly， the conception of PSF in traditional optical imaging and the key role of PSF in optical system design are introduced， and several algorithms for imaging restoration using PSF and imaging evaluation indices are briefly explained. On this basis， the connotation of PSF is re-examined from the perspective of information transfer under the framework of computational imaging， and relevant researches in the field of computational imaging are summarized from the two aspects of narrow and generalized optical systems. Finally， the application prospect and development trend of PSF engineering technology are prospected.