Hainan Rainforest National Park is cut across by the Middle-line Expressway of Hainan Island from northeast-southwest direction, which might affect the landscape pattern and ecosystem integrity and functions, and cause potentially ecological risk. In this paper, we chose the regions within 3 km at two sides of the expressway as the study area, and quantitatively evaluated their landscape patterns for three years, i.e. 2013 (before expressway construction), 2016 (expressway under construction), and 2019 (expressway completed), based on GIS, Fragstats and landscape ecology theories. We found that the expressway (including construction areas) in 2016 was 325.51 hm², forest cover decreased slightly but forest patch density increased. Farmland dominance decreased as a result of increased farmland fragmentation, although its area increased slightly. In 2019, when the expressway completed, the expressway area decreased slightly and forests increased, due to afforesting along the expressway. However, the cohesion index of forest and farmland decreased in 2019, which indicated a lower connection degree and a higher landscape fragmentation. The moderate and high ecological risk area along the expressway had been increasing year by year. Nevertheless, the landscape along the expressway remained relatively unchanged and showed little effects to the ecosystem integrity and functions. The habitat isolation and fragmentation caused by the expressway probably possess negatively ecological effects in future. Particularly, the expressway crossing section in the National Park located in the most important water supply and conserving area of the Hainan Island, i.e. triangle area of Mt. Limu, Yingge, and Wuzhi, where is the headwater region of the three biggest rivers of the island. It is necessary to build overpass woodlands to increase ecosystem connectivity, to build the constructed wetlands to purify runoffs from the expressway, and to establish long-term monitoring sites for enhancing ecosystem functions such as water supply and conserving potential and water purifying ability.