Abstract: Under the context of the deepening “dual-carbon” strategy and the green transformation of the environmental protection industry, sewage treatment plants, as high-energy-consuming infrastructure, generally face industry pain points such as high proportion of electricity consumption, high operating costs, single energy structure and low utilization efficiency of idle space. The optimization of energy structure and intensive utilization of resources have become the core direction of industry development. This paper takes a sewage treatment plant as the research subject. Based on the plant’s layout of structures and facilities, operational characteristics of the process, and solar energy resource conditions, it systematically conducts research on the design and application of a photovoltaic power generation system. It elaborates in detail on core aspects such as the selection of PV modules, overall system layout, structural design, power generation estimation, and consumption analysis. The study focuses on analyzing the synergistic effects between the sewage treatment plant and the PV power generation system, and verifies the technical feasibility and economic viability of the system through engineering practice. This study proposes a photovoltaic layout scheme and a high-consumption operation mode adapted to multiple scenarios of sewage treatment plants, and the three core innovation points provide a comprehensive technical reference and engineering demonstration for the photovoltaic application of similar municipal environmental protection projects, which is of great significance for promoting the large-scale application of renewable energy in the municipal field.