Driven by the global energy transition and the urgent ‘‘dual carbon” goals

regional integrated energy system (RIES) planning is undergoing a paradigm shift from carbon reduction to negative carbon emissions. This paper provides a comprehensive review of the theoretical frameworks and technical pathways for RIES planning from a carbon-centric perspective. A key contribution is the proposed Carbon-Energy-Economy (CEE) triple-dimensional governance framework

which endogenizes carbon factors into planning decisions through emission constraints

trading mechanisms

and capture technologies. We first analyze the fundamental characteristics of RIES and their critical role in achieving carbon neutrality

detailing advancements in multi-energy coupling models

energy router concepts

and standardized energy hub modeling. The paper further explores multi-energy flow analysis methods

and systematically compares the applicability and limitations of various planning algorithms

with emphasis on addressing uncertainties from renewable integration.Finally

we highlight the integration of artificial intelligence with traditional optimization methods

offering new pathways for intelligent

adaptive

and low-carbon RIES planning.This review underscores the transition towards data-physical fusion models

cooperative uncertainty optimization

multi-market planning

and innovative zero/negative-carbon technological routes.