China's coastal areas have a large latitude span, and the cooling and heating loads of buildings are diversified. The wind-solar complementary system was considered to meet the cooling and heating needs of buildings, to solve the problem of energy use in coastal islands. To explore the applicability of the wind-solar complementary system and the cooling and heating requirements of buildings in coastal islands, this paper analyzed the characteristics of wind-solar resources in 23 coastal cities and the characteristics of the cooling and heating requirements of a building throughout the year. Based on the seasonal and annual comparisons of wind-solar complementarity coefficient, correlation coefficient, immediate load satisfaction rate, immediate energy utilization rate and supply-demand synergy, the applicability of wind-solar system in different regions was discussed in a multi-dimensional way, and three types of adaptability were generated by cluster analysis. The results show that the degree of wind-solar complementarity in coastal islands has certain regional characteristics. With the decrease of latitude, the applicability of the wind-solar complementarity system increases, and the smaller the fluctuation of cold and hot demand is, the stronger the applicability of the wind-solar complementarity system is. This study has a certain guiding significance for the promotion and application of wind-wind mixed energy supply systems in coastal areas of China.