Current 2D or 3D electronic map could not show the information of 3D terrain and ground object from multi-ple perspectives simultaneously directly and really.And it is difficult to satisfy with the city construction and manage-ment with the high speed development of the digitalization and informatization.So the system of 3D city photonics map is designed based on holographic display technology.And an algorithm of phase CGH(Computer-Generated Holo-grams)with inverse diffraction is proposed.Firstly,the raw 3D point clouds data are obtained by the theory of struc-ture from motion.Then the diffraction fringes of 3D reconstructed terrain data are obtained from the diffraction results by the reverse strike means.The allotted units of diffraction fringes are transformed into the interference fringes of hol-ogram by the method of table lookup.And the holographic interference fringes are recorded on the film of silver plate.The true 3D photonics map is reproduced under white light irradiation.At last,3D hologram is displayed on the devel-oping experimental platform and printed on the holographic silver halide plate by the help of others.The experimental results indicate that the design proposal is feasible,the efficiency and accuracy of algorithm are higher,and the display effect of hologram has embodied the basic properties of photonics map.%针对现有电子地图不能同时多视角、直观、真实地显示三维地形地貌信息，难以满足高速发展的数字化、信息化城市的建设和管理需求的问题，研究了一种运用全息显示技术的3D城市光子地图系统设计，提出了一种采用逆向衍射纯相位计算全息算法。首先运用 SfM （Structure from Motion）理论获取3D 地形点云数据，然后从衍射结果出发，将重构的3D 地形信息作为衍射目标图像，逆向求取需要的衍射条纹；再通过分配衍射单元的查表算法转化为全息干涉条纹，写入银盐干板记录材料，在白光照射下再现为真三维光子地图。3D 全息图在自行搭建的实验平台得到了显示，并借助外协设备将校园局部全息图打印在银盐板上。实验结果表明，系统设计方案可行，算法的运算效率和准确度较高，全息图的显示效果体现出了光子地图的基本属性。
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