With the rapid development of the Internet of Things (IoT) and Artificial Intelligence (AI) technologies, their manufacturing processes have led to an increase in greenhouse gas (GHG) emissions and a significant increase in electronic waste, which adversely affects the global environment. Consequently, green and low-carbon transformation of smart products is imperative. To address the limitations of combining low-carbon principles with complex smart product design, this study proposes an innovative "LCD-AHP-TRIZ" methodology that integrates the full life cycle design (LCD), analytic hierarchy process (AHP), and theory of inventive problem solving (TRIZ) to systematically resolve low-carbon smart conflicts in product design and propose solutions. The method utilizes LCD to construct a low-carbon demand table for the life cycle of smart products, AHP to quantitatively assess the importance of indicators, and TRIZ theory to resolve conflicts, thereby successfully integrating low-carbon demand into smart product design. The applicability and effectiveness of this method were verified using a smart dehumidifier as a case study. The results demonstrate that the method can systematically identify low-carbon design requirements, solve innovation problems, and provide scientific strategies for sustainable development of smart products.