The island sustainability is evaluated by establishing the parameters such as emergetic ecological deficit/surplus, fishery footprint intensity (D), social development pressure index (I) and economic coordination index (Q) based on emergy theory and ecological footprint method. For the case study, Zhoushan of Zhejiang Province, a typical island city, is taken as the example. The results show that from 2003 to 2017 the emergy footprint and the emergy carrying capacity in Zhoushan were all on a rising trend; the emergy ecological footprint per capita increased by 15.78 hm² with an amplification of 63.26% and the emergy carrying capacity per capita increased by 5.20×10² hm² with an amplification of 82.86%, of which both the emergy footprint of the land used for fossil energy and the socio-economic carrying capacity increased the most, while the natural carrying capacity decreased. The emergetic ecological deficit/surplus and the economic coordination index cannot fully reflect the regional sustainability. The continuously increasing of the regional fishery footprint intensity indicates that the current fishery economic model doesnot meet the requirements of sustainable development. The increasing of the social development pressure index further indicates that the development status in Zhoushan has deviated from the sustainable track.