Under the guidance of the "dual carbon" goals, green and low-carbon transformation has become the key path for the high-quality development of the cement industry. The industrial application of energy-saving and carbon-reduction technologies is the key to achieving industrial emission reduction. This article takes a 2500t/d cement clinker production line as the research object, analyzes the problems existing in the kiln system of the production line, and proposes energy-saving renovation goals and renovation plans based on low-carbon cement technology, including optimizing the structure of the preheater to reduce system pressure loss, improving the ventilation in the kiln to enhance heat exchange efficiency, and applying the fourth-generation cooler and high-temperature SCR denitration system, etc. After the transformation, the standard coal consumption per ton of clinker decreased by 7kg/t.cl, the power consumption dropped by 3kW·h/t.cl, the resistance of the preheater system dropped to below 5000Pa, and the temperature at the C1 outlet decreased by 40℃. NO_X≤50mg/Nm3, ammonia escape ≤5mg/Nm3, with remarkable energy-saving and consumption-reducing effects, providing a replicable technical model for the transformation of similar production lines.