Coastal zone, a key area for human settlement and development of economic, has been affected to a certain extent with human activities and rapid urbanization, resulting in landscape pattern changes and environment deterioration. This research field has become the study hotspot of many scholars. Based on ArcGIS and Fragstats, four phases of land use vector data of Haikou coastal zone in 1988, 2000, 2009 and 2017 have been processed. Furthermore, with the help of grid GIS method and Kriging interpolation method, the landscape ecological risk index model has been set up. Thus, we comprehensively evaluated the landscape ecological risk of the coastal zone of Haikou City. The results showed that: (1) the landscape area varied greatly and the main landscape type was construction and the cultivated land. (2) Human activities had the strongest interference to the landscape between 2000 and 2017, and the maximum value of separation, interference and vulnerability appeares in this time. (3) The average ecological risk in the study area increased from 0.3424 to 0.4468. The transformation of ecological risk level was generally from low to high. In addition, the spatial distribution presented a decreasing trend from the middle to the east-west and inland to the coast, as well as the high-level risk areas gradually spread to the coast. The area with high and extremely high ecological risk were mainly distributed in the Haikou Built-up Area, the Nandu River bank, Meilan Airport, Mangrove Reserve, and the State Farm in Sanjiang Town. (4) The main reason for the increased ecological risk values is the area of green space and water is reduced and the distribution tends to fragment and separate, as the development of city and port industry. The results of this study can provide scientific basis for optimization of the landscape pattern, protection of land resources and sustainable development in the coastal zone of Haikou City.