Quantitative assessment of regional human activity intensity can reflect the relationship between people and environment, which can provide a scientific basis for landuse-related decision making and eco-environment construction. Based on the land use/land cover data with 1 km resolution, we quantitatively evaluated the spatial-temporal features of human activity intensity in Hainan Island from 1980 to 2018. On this basis, we analyzed the overall change and spatial correlation of human activity intensity and explored its driving mechanism. The results showed that: 1) The main types of land use were woodland and farmland in the study area in 2018, accounting for 62.85% and 25.27%, respectively. Only bulit-up land increased sharply, and areas of all other land use types reduced from 1980 to 2018. The areal reductions of farmland and grassland were the largest and the decreases were 397.81 km² and 303.02 km², respectively. 2) Human activity intensity gradually increased from 10.54% (1980) to 12.86% (2018), risen by 22.01%. Before 2000, it was relatively stable and after that, it grew fast. 3) The spatial distribution of human activity intensity was high in the coastal areas and low in the central part of the island. Human activity intensity showed significant spatial agglomeration effect and the hotspots were concentrated mainly in areas of rapid urban development, such as Haikou City and Sanya City. 4) The human activity intensity in Hainan Island was mainly driven by government policy, rapid population growth, economic development, and so on.