[Abstract] In order to reveal the law of space-time change of landscape ecological risk in coastal areas, the GIS technology and semivariogram analysis methods were adopted, landscape interference index and landscape vulnerability index were used, the land use ecological risk model of the FangChenggang city was constructed from the perspective of Production-Life-Ecological Spaces, and the spatio-temporal differentiation characteristics of landscape ecological risk of FangChenggang city from 2000 to 2019 were deeply studied. The results show that :from 2000 to 2019, the landscape pattern of the Fangchenggang city changed significantly, and the grassland ecological space area decreased the most, which reduced 34 557.59 hm2 and mainly flowed to the forest ecological space. In addition, a total of 32 962.59 hm2 had been reduced. Between 19 a, the area of lowest ecological risk area continued to decrease, which was particularly significant in the last 10 a. After the area of the lower ecological risk area increased by 9 a and decreased by 10 a, it showed an overall trend of increase. The area of medium, higher and highest ecological risk areas was increasing, and the area of the last 10 a was much higher than that of the first 9 a. From 2000 to 2019, the overall degree of ecological risk and environmental quality degradation in all regions of Fangchenggang city were deepened, and the latter 10 a was obvious. It is concluded that the study of the change of landscape ecological risk in Fangchenggang city is of great significance to promote the coordinated development of its ecological environment and regional economy, and perfect the theory of landscape ecological risk in Bay city.