This research attempts to establish 3D display mode of environmental harmful electromagnetic field for indoor mobile augmented reality (AR) systems. However, the use of today's various energy and fluid digital simulation mode for showing 3D electromagnetic field in AR systems will encounter insome problems such as: (1) in the space between objects, the distribution of electromagnetic wave is not easy to display through a single 3D model, (2) the attenuation gradient of the electromagnetic wave is not easy to display in 3D rendering, (3) the phenomenon of superposition from multiple electromagnetic wave overlapping is not easy to simulate in 3D mode, (4) the colorful gradient display method commonly used in 2D is not suitable for 3D volume, (5) the opaque front 3D objects shield rear objects, (6) the colors of front semi-transparent 3D objects blend with the colors of rears, (7) the distance between front weak electromagnetic 3D models and the rear stronger ones is not easy to distinguish. Therefore, this research presents a ＂Transparent Reflective Point-cloud Crystal＂ model by using visible light source to irradiate transparent reflective octahedral crystals in simulation of electromagnetic wave, can overcome the above-mentioned problems. In addition, the value of electromagnetic waves in campus are measured for augmented reality system to present ＂high and low frequency electromagnetic wave source＂, ＂the highest radiation value points＂, ＂the source orientation of strongest electromagnetic radiation measured＂, ＂3D influence area of harmful electromagnetic source＂, ＂the safer path way suggested＂ in order to help users aware of the electromagnetic field in the living environment.