To address the collaborative optimization of offshore wind-thermal-storage systems，this paper proposes an aggregation optimization method based on membership degree analysis.The proposed method enables dynamic resource aggregation and flexible scheduling by modeling and optimizing offshore wind farms，thermal power plants，and energy storage systems.Specifically，the aggregation set is generated using the Cartesian product，and initial aggregation schemes are filtered by introducing constraint conditions.A comprehensive evaluation is then conducted using membership degree analysis across three dimensions：wind power accommodation rate，economic benefit，and coordinated frequency regulation capability of thermal power.Simulation results demonstrate that the optimized aggregation configuration significantly reduces system operating costs while enhancing the coordination of thermal power frequency regulation capability.A case study based on offshore wind-thermal-storage resources in Zhejiang Province，China，demonstrates the effectiveness of the proposed method and provides new theoretical support and technical pathways for large-scale new energy accommodation and optimized system operation.