Computer VR technology has been widely used in landscape design. This paper analyzes the auxiliary use mode and detail optimization process of this technology in landscape design, and gives the comparative experiment of indoor and outdoor landscape design. Firstly, landscape design planning and design based on VR technology; secondly, the detailed optimization process of the combination of VR and VR-GIS is analyzed; finally, aiming at the problem of poor energy-saving effect of traditional methods, the energy-saving optimization design of data acquisition system is carried out. The data collector in the data acquisition system uses the method of contrast image of visual image to collect data, so it consumes a lot of power in the process of using. Therefore, the data collector and control power system are optimized, which can effectively reduce the energy consumption. In the process of virtual image establishment, edge correlation operator is used to calculate correlation, so as to achieve low power consumption. On this basis, the auxiliary use and detail optimization in landscape design are given by using Lumion virtual reality (VR) platform. The experimental results show that the visual modeling error of this method is stable between 1 and 3%, the error is small and the stability is good; the average rendering time of batch objects is about 8.9 s, which is an efficient auxiliary use and detail optimization method for VR landscape design.