To analyze the spatial and temporal variation of the leading edge of Ｓpartina alterniflora in Yancheng Wetland National Reserve, Jiangsu Province, an improved window of opportunity model based on Ｓpartina alterniflora reproduction mode and minimum disturbance-free time of remote sensing inversion was proposed, and the evolution pattern of Ｓpartina alterniflora leading edge and its driving mechanism were analyzed through the correlation analysis and mean absolute error to verify the accuracy of the model. The results showed that from 1998 to 2010, the front of Ｓpartina alterniflora advanced to the sea. From 2010 to 2020, the foreedge presents a W-shape trend of siltation-erosion-siltation-erosion-siltation from north to south. In 2020 and 2021, the Ｓpartina alterniflora front continued to erode and retreat in the north, remained relatively stable in the middle, and moved seaward in the south.