In this paper, a design method of multi-focal intraocular lens is proposed. Dammann zone plate, which consists of a series of concentric rings, is a practical optical element which introduces the phase modulation idea of Dammann grating into the traditional band plate. Through modulating the diffraction order, it can produce a series of axial focal spot distribution in the light field behind the focusing lens. Moreover, by combining the focusing lens with different numerical apertures, the intensity distribution of the focal spot will also change to a certain extent. Through theoretical simulation and experimental verification, it provides an effective design method for fabrication of multi-focus intraocular lens. The multi-focus intraocular lens has five focal points, which can improve cataract patients' vision at different distances simultaneously and provide them with clearer and more detailed images.