Compared with the traditional two-dimensional (2D) projection display, three-dimensional (3D) projection display with good market prospect not only enables the observer to see a more vivid projection image, but also provides 3D information. On the basis of principle of information optics, we put forward a process to a 3D holographic projection, which is based on a holographic lens array screen: the images sampled by camera array are transformed and projected by projector arrays to a holographic projection. The projection consists of holographic optical elementsholographic lens array, through which the projection beam is transformed into directional diffraction integral, reproducing the 3D information of the object and realizing 3D projection. The experiment making the holographic lens array is described, which can control the orientation of the projection beam diffraction; and the method of achieving 3D projection by using holographic optical elements is investigated.