<p>The construction of smart grids is crucial in responding to rapid urbanization and growing energy demand. However, assessing the benefits of their investment is one of the main challenges in the construction process. This study presents a new decision-making model aimed at addressing the smart grid investment benefit assessment problem from a dynamic perspective. First, dynamic Fermatean fuzzy Schweizer–Sklar aggregation operators with specific properties are proposed to aggregate the dynamic evaluation information. Then, we construct an evaluation index system with economic, technical, environmental, and social criteria. Furthermore, a dynamic multicriteria decision-making model, referred to as the dynamic Fermatean fuzzy combined compromise solution method, is proposed based on the proposed aggregation operators. Finally, to validate the practicality of the proposed framework, we conducted a detailed assessment of the investment benefits of four smart grid projects.&#xa0;The primary novelty of this study lies in its simultaneous consideration of dynamic temporal factors and high-order fuzzy uncertainty within the investment evaluation process, which has been largely overlooked in prior work. Our approach can adjust to changes in information reliability and importance over time, improving the adaptability of decision outcomes. The findings reveal that the proposed framework can effectively integrate various complex evaluation data and accurately reflect the performance of each smart grid project across different dimensions. Sensitivity and comparative analyses verify their credibility and applicability in practical applications, demonstrating their superiority in handling dynamic decision-making scenarios. This model provides power companies with a set of tools and methods to help them conduct more accurate investment assessments.</p>