Abstract: In terms of islands and coastal vulnerability assessment process, there are technical difficulties in building the model, indexes screening, weight determination and data acquisition and assimilation. Among them, determining the weights of vulnerability assessment indexes is an important part during the evaluation process, so related research should be carried out as soon as possible. Based on mathematical method and the previous studies, according to the characteristics of the subjective and objective weight method, applying the AHP weight method and entropy weight method, a new method which is more scientific and reasonable than previous subjective and objective empowerment studies is put forward. And finally, according to the method, to determinate the weight of partial vulnerability evaluation indexes shows the effectiveness and practicability of the method.