The purpose of this study is to investigate the modification characteristics of the island man-land relationship and the influences of human activities on the island resources and environments in 1996-2016 of Changshan Archipelago. We analyzed the changes of balance between supply of resource environment and demand of human by the improved emergy ecological footprint model. We also examined the relationship between the development of coastal economy and emergy ecological footprint by the decoupling elasticity equation utilizing available statistical data of Changshan Archipelago from 1996 to 2016. The results showed that:(1) the rapid development of economy and the improvement of living standards promoted the swift growth of emergy ecological footprint in Changshan Archipelago. The economic development and urban expansion led to the occupation of land resources and destruction of environment, which reduced the ecological carrying capacity. (2) The overexploitation of marine fishery resources and the growth of fossil energy consumption made the relationship between human and environment in Changshan Archipelago to remain in the state of ecological deficit and show a trend of expansion. Various ecological footprint accounts denoted different meanings that required differential treatments in accordance with specific conditions. (3) The decoupling effect between emergy ecological footprint and GDP in Changshan Archipelago mainly went through the transition process successively by expansion connection, weak decoupling, expansion connection, weak decoupling, and strong decoupling. The speed of economic development, industrial structure, and economic growth pattern were important factors influencing shift of the decoupling between economic development and emergy ecological footprint. (4) The emergy ecological footprint transferred its influence to the island from the ocean.