A method of imaging on multiple focal planes based on fractional Fourier transformation is presented. It is used to compute the holograms, so that different images are projected at different depths in the same system. By using synchronization information sent by the spatial light modulator, the circuits control the switch of the polymer doped liquid crystal screens. That means only the one with the right depth is switched off corresponding to the projected image, others let light pass through. With the sequential loaded holograms on the spatial light modulator, different holographic images are presented on multiple focal planes. Three-dimensional (3D) display by holographic display imaging on multiple focal planes is realized as a result of visual staying phenomenon. The imaging depth can be adjusted according to parameters of the optical system and sampling conditions. Besides, the system is simple and easy to carry out.