To address the challenge of dynamically displaying the characteristics of ancient murals and providing users with an authentic and clear artistic design effect, this study examines the application of 3D VR technology in displaying ancient cultural relics. It explores the use of 3D VR technology in cultural relic art design, the implementation process of 3D VR technology, and the construction and application of 3D cultural relic models. The first task in the current paper is to detect image feature points utilizing the oriented fast and rotated brief (ORB) framework; a homogenization strategy is adopted to process the extracted feature points, and a word bag model (BoW) is used for feature matching. Then, in the stage of system camera attitude, initial value estimation, perspective n point (PnP), and nonlinear optimization method are combined to provide an initial value closer to the optimal value for back-end optimization. In the back-end optimization, the initial attitude of the camera is iteratively optimized by using the beam adjustment (BA) method to get the optimal attitude of the camera. The BA method optimizes the camera's pose parameters (including position and direction) by minimizing the reprojection error. In the 3D reconstruction of murals, accurate camera pose is the foundation to ensure the quality of reconstruction. Through iterative optimization, the BA method can gradually adjust the camera pose to make it closer to the true value, thereby improving the accuracy of reconstruction. Finally, a master data point is set up, which is used to divide 3D point cloud data of the reconstructed mural, assign reconstruction tasks, collect and dynamically display the reconstructed results, and complete the virtual reconstruction of point cloud data of the reconstructed mural. The experimental results show that 3D VR technology can enhance the artistic design effect of cultural relics, and user satisfaction is high, improving the sense of viewing cultural relics. This indicates that 3D VR technology is feasible in the dynamic display design of ancient mural characteristics.