Based on the three-dimensional virtual building-simulation design and implementation method of the gymnasium, when the building space is subjected to virtual reality and simulation design, based on the constructed building space coordinate system and scale, the position and parameters of the building are used to construct a mathematical model of the building space component., The mathematical model of each component is integrated to build a mathematical model of the overall building space. OpenGL virtual reality technology is used to expand the target building based on the mathematical model of the target building space. The target building is given materials and texture characteristics to obtain the ideal 3D virtual view of the building space. The 3D virtual view of the building space is 3D rendered and displayed. The vivid 3D virtual renderings of the building space are animated using animation design technology. The experimental results show that the proposed method has good point-line rendering and overall rendering effect, can obtain more realistic 3D virtual building based gym simulation design results, and has high interactivity and practicability.