Exploring the fundamental technical problems and countermeasures will help improve the theories and technologies regarding the low-carbon construction of canal engineering (LCCCE) and provide references for future canal construction. This study reviews the history of canal engineering in China and clarifies the necessity of LCCCE from the perspectives of engineering commonality and canal individuality. The difficulty of canal engineering in the new situation is to improve low-carbon construction on the basis of ensuring reliability. Therefore, the fundamental technical problems of LCCCE focus on low-carbon security. Based on the practice of low-carbon technology research in the century-long project of the Pinglu Canal, this study focuses on the following fundamental technical problems: (1) efficient application of canal building materials, (2) efficient utilization of old and new structures, (3) multi-dimensional recycling of solid wastes, (4) durability guarantee and biodiversity protection of canals, and (5) low-energy consumption in canal construction, operation, and maintenance. A low-carbon construction technology framework consisting of “reduce, reuse, recycle, resilience, and renewable energy” (5R) is proposed to accurately address the fundamental technical problems of LCCCE. The LCCCE is still in its infancy, and it is recommended that the academic and engineering communities continue to focus on this emerging field.