For traditional pipeline inspection systems that exist non-sufficient timeliness in the network data, spatial location relationship between networks is not intuitive and with poor continuity problems, this study uses the mixed reality, 3D modeling, and spatial positioning technology, in accordance with the need of pipeline inspection, dynamically constructs the pipe network and fuses with the actual features, intuitively shows the spatial location relationship between the networks and the real-time running condition of the pipeline network, designs and implements pipe network system based on mixed reality. Aiming at the problem of pipeline network model positioning, this study designs a spatial coordinate transformation method to complete the spatial mapping between virtual pipeline network and real pipeline network. For the construction and optimization of pipeline network model, this study proposes a dynamic construction and optimization method to realize the dynamic loading of pipeline network and the smoothing of local connections. The experimental results show that the proposed method can accurately integrate the virtual model with the real pipeline network, smooth the connection of the virtual pipe, and clearly and intuitively show the spatial relation of the pipeline.