In response to the L-shaped irregular shape, dense steel bars, and high requirements for the appearance of clean water in a certain underground substation, the surface appearance quality of the concrete structure is required to be high. Therefore, the use of self compacting clean water concrete construction technology is comprehensively considered. This article compares and studies the selection of concrete materials and coarse aggregate requirements through on-site sample tests, controls the water cement ratio and sand ratio, and conducts reasonable mix design. The selection of mirror red templates and the treatment of template joints ensure the quality of the formation of plain concrete, enabling the application of self compacting plain concrete construction technology in underground substations and providing reference experience for subsequent underground substation projects.