Land use change has a certain impact on regional ecological environment. It's a great significance to evaluate the regional ecological security from the perspective of landscape ecology. Based on the remote sensing images of 1995, 2005 and2015, the ecological security evaluation model was constructed to reveal the response of landscape ecology security status to typical land use change in typical karst plateau wetland. The landscape pattern and landscape ecological security evolution of the study area in past 20 years were analyzed. The results showed that: during the past 20 years, the degree of fragmentation of forest land and grassland in the study area was obvious; water landscape area increased constantly but landscape fragmentation level decreases sustaining; Areas of plough and construction land increase in these years. High level ecologic security areas were mainly concentrated around the survey area, the majority of forest land in the northeast and southwest, the medium and low level ecological security areas were mainly concentrated around the Caohai Lake area, but the medium-high and high level ecological security areas were mainly distributed in the central area with plough. Low and low-medium level ecological security areas were rising gradually in survey areas, which mainly concentrated on Caohai Lake construction areas; high level ecological security areas decrease gradually and fragmentation level increase; medium-high level ecological security areas increase.