Abstract: The Pinglu Canal is the backbone project of the new western land–sea corridor and the first canal project built since the founding of the People's Republic of China to connect a river with the sea. The three hydro-junctions—Madao, Qishi, and Qingnian—are the key and most challenging nodes in canal construction. The high-strength mass concrete used in the locks of these hydro-junctions generates substantial carbon dioxide emissions, while temperature control of large-volume concrete in hot environments remains difficult. Moreover, existing temperature control measures, such as concrete pre-cooling and structural cooling with circulating water, are highly energy-intensive. To address these challenges, research on green and low-carbon construction technology for large-volume concrete structures was carried out through structural optimization design, numerical analysis, full-scale on-site testing, and practical application. An innovative porous large-volume concrete structure and green temperature-control technology have been proposed. The results indicate that porous structures can reduce concrete use by about 14% compared to solid structures, while maintaining reliable structural stress performance. The porous structure can effectively dissipate the hydration heat of concrete through ventilation and the injection of normal-temperature water into the holes, achieving a desirable temperature-control effect. Among them, the temperature-control effect of airflow through the holes is essentially equivalent to that of conventional cooling water pipes, whereas injecting normal-temperature water into the holes achieves the best outcome, reducing the temperature peak by about 9.5 ℃. Accordingly, the proposed scheme of "non-pre-cooled concrete + injection of normal-temperature water into the holes of the multi-hole structure" can successfully replace the traditional scheme of "pre-cooled concrete + structural cooling circulating water", while still meeting design requirements. This technology has been applied and practiced in the main navigation wall of the Madao junction, featuring energy conservation, high efficiency, and carbon reduction. It contributes to the construction of a green and high-quality Pinglu Canal project. The porous temperature-control technology for large-volume concrete is an innovative breakthrough in addressing the dual challenges of temperature regulation and crack prevention. It effectively mitigates the thermal effects in large-volume concrete, thereby promoting energy-saving, low-carbon, and green construction practices in engineering. It has good application and promotion value for gravity-type large-volume concrete structures with relatively little reinforcement. A novelty search conducted by authoritative institutions, both domestic and international, confirmed that no similar research has been reported. Furthermore, expert evaluations have unanimously recognized the value of the results. This technology thus provides an important reference for advancing green and low-carbon construction in future major projects.