To accurately assess the offshore wind power development potential in the southeastern coastal provinces of China, this study employs a farm-scale analytical approach, combining historical wind speed data, marine geographical information, and wind turbine layout optimization strategies. A suitability evaluation framework is established, incorporating factors such as wind speed, wave height, water depth, and protected area restrictions, along with a standardized wind turbine spacing layout scheme. Additionally, a Gaussian wake model is used to quantify wake effects at the wind farm level. The results indicate that the offshore wind potential in the five southeastern provinces can meet 77% of the regional electricity demand. Optimizing wind turbine row configurations and spacing can balance wake losses and overall power generation potential. The application of deep-sea floating wind turbines and large-capacity turbines will significantly improve resource utilization. These findings are of great significance for rational planning of regional wind power development and the optimization of construction decisions, providing a pathway for the low-carbon transformation of regional energy structures.