Marine ecological restoration is a crucial strategy for stopping the degradation of the marine ecosystem, and the comprehensive benefit assessment of the restoration is a crucial tool for evaluating all of its attributes and identifying any gaps between the goals and the actions. Currently, the analysis of cumulative benefits from the perspectives of multiple factors, multiple projects, and multiple dimensions of value, and the investigation of synergistic strategies for the target-cost-benefit triad are still lacking in China's marine ecological restoration research. In view of this, this article proposed an indicator system for the comprehensive benefits of marine ecological restoration at the city (county) level and established the corresponding assessment methods and grading standards, taking ecological benefits, economic benefits and social benefits as the core framework. The rate of change in seawater quality, the rate of shoreline ecologization, the rate of change in the quantity of fishery resources, and the ecosystem restoration index were indicators that fell under the category of ecological benefits, which were used to gauge the effect of marine ecological restoration on the improvement of the quality of marine ecosystems and the conditions for the survival and development of the region. The economic input-output ratio served as the main indicator of economic benefits, which were used to gauge the value realization capacity of ecological restoration on marine ecological products. Social benefit indicators included social public involvement, satisfaction with ecological consequences, influence on residents' lives, and influence on production and life, which were used to gauge how well the general public viewed the preservation of social fairness and the benefits of marine ecological restoration. Throughout the process of building the assessing indicator system, consideration was given to the effective integration of the system with relevant policy planning, technical standards, and management practices of marine ecological restoration, in addition to the applicability of the assessing indicators, the scientific validity of the assessing methods, data availability, and the rationality of the assessing classification, which helped make research findings more applicable and broadly applicable. It's crucial to point out that the time-space scale constraint of a full benefit evaluation led to this study's construction of the ecological restoration indicator calculation method just from the vegetation community and ecological space viewpoints. In the long-term follow-up assessment, the ecological restoration effect assessment component needs to be strengthened. Furthermore, case verification is required for the assessment indication and scoring threshold determination to increase the trustworthiness of technical approaches. The assessment indicator system can give government administrative departments the technical assistance to complete pertinent assessment work and multi-objective decision-making. It can also offer new approaches and concepts for the advantageous study of marine ecological restoration.