With the comprehensive advancement of the “dual carbon” goal, carbon emission reduction policies have become increasingly prominent in China’s green development landscape, serving as a crucial instrument for coordinating economic transformation and ecological civilization construction. Local governments are the primary executors of these policies. In practice, how to translate the central government’s policy objectives and institutional requirements into concrete actions while balancing local resources and development demands has become the key to successful policy implementation. Focusing on the contextual practice of policy implementation, this paper identifies four prevalent types of implementation deviation by local governments in fulfilling carbon reduction tasks: mechanical implementation, selective implementation, symbolic implementation, and “one-size-fits-all” implementation. These deviations are not random occurrences but represent specific behavioral choices made by local governments under particular institutional constraints and governance structures, reflecting deeper issues such as imbalanced incentives and misaligned authority and responsibility within central-local government relations. Based on the analytical framework of the central-local principal-agent relations, this paper analyzes the inherent causes of implementation deviations: The “rational eco-man” mindset leads to policy cognitive biases; information asymmetry exacerbates regulatory evasion; current indicator allocation mechanisms restrict local initiative; and the assessment and incentive systems malfunction. Based on this analysis, the paper constructs a pathway to address these deviations from four dimensions: concept, technology, method, and institution. At the conceptual level, it clarifies the promotion logic and implementation pace of the “dual carbon” goals. At the technological level, it strengthens information-sharing mechanisms and collaborative supervision capabilities. At the methodological level, it promotes regional collaboration and improves market trading mechanisms. At the institutional level, it optimizes assessment methods and incentive-constraint systems. These pathways can reinforce the transmission chain of carbon reduction policies from central design to local implementation, enhance the precision of policy implementation and governance effectiveness, and provide theoretical support and institutional insights for achieving the “dual carbon” goals.