In order to solve the problem of instability of offshore wind power generation, and with the help of the driving effect of offshore wind power, promote tidal current power generation from the demonstration application stage to a new stage of industrial development. Based on the Geographic Information System(GIS) and Multi-Criteria Decision-Making(MCDM) method, this paper proposes a method framework of wind and tidal current zoning. The framework includes two stages: the determination of development areas and the evaluation of development suitability, and the two criteria sets: exclusion criteria and evaluation criteria. To reduce the subjective deviation in the decision-making process and give full play to the advantages of multi-domain expert evaluation, the Group Fuzzy Analytic Hierarchy Process (GFAHP) is proposed to calculate the criteria weight. Meanwhile, considering the relative proximity of the alternatives and the change trend of the attribute value, the Grey Relation Analysis-Technique for Order Preference by Similarity to an Ideal Solution (GRA-TOPSIS) is used to calculate the suitability index. Finally, the decision-making framework is applied to the sea area of Shandong Province to provide a reference for the development of wind and tidal current in Shandong Province.