Abstract: Similar hemispherical projection technology provides visual experience of simulation training for underground staff. For the narrow and long and dusky features of life-saving cabin, similar hemispherical display architecture is in favor of clear showing the life-saving cabin of coal mine. The article mainly discusses basic theory of getting fisheye image in similar hemispherical projection, and gets the virtual fisheye image of life-saving cabin by ray tracing calculations in Unity combined with the key technologies of fisheye image theory and creating fisheye angle image.