When applying landscape connectivity to the study of landscape pattern changes, it is important to choose the appropriate distance threshold, which affects the analysis of landscape connectivity in the study area. If the distance threshold is set too low, the patches in the area will remain unconnected, and fragmentation will be severe, whereas if the distance threshold is set too high, the patches in the area are interconnected and grouped together. However, neither of these scenarios is likely to truly reflect the actual condition of the landscape in the study area. Using an appropriate distance threshold will facilitate the identification of key patches in the landscape and the discovery of vulnerable areas, both of which are important for the dynamic analysis of landscape patterns and ecological restoration studies. The present study investigated this principle using Landsat 8-OLI remote sensing images of a wetland ecosystem of the Tianjin Binhai New Area, taken on April 14, 2017. The research area was divided into different focal landscapes, in order to prevent software stalling and reductions in data processing speed that could have resulted from the large study area and provide a new analytical idea for this field. The focal landscape was the same size area, based on the habitat area of the migratory birds in the study area, and was analysed by Thiessen polygon analysis in ArcGIS. The number of links, number of components, equivalent connectivity area, and landscape coincidence probability were selected to characterize the landscape connectivity, and a total of 11 distance thresholds (100, 200, 400, 600, 800, 1000, 1500, 2000, 3000, 5000, and 8000 m) were selected to draw the ‘Landscape Connectivity Index-Distance Threshold’ curve, which was used to study the trend of each index under different distance thresholds. By comparing the overall landscape patch and the focal landscape connectivity index with distance thresholds, the optimal distance threshold for the study area was determined. (1) The optimal distance thresholds selected by the two methods of focal landscape and overall landscape patch were the same, and the proposed method provides new ideas for future regional landscape analysis and more complex ecological landscape pattern research. (2) The range of 400-800 m can be used as suitable distance threshold ranges for the dynamic change of landscape pattern and restoration of ecosystems in the Binhai New Area. In this interval, the connectivity of the habitat patch in the study area was relatively stable, which clearly illustrates the distribution of the patches and helps to identify the important patches in the landscape. (3) Through further research, 400 m was finally selected as the optimal distance threshold for the connectivity of the wetland ecosystem in Tianjin Binhai New Area. These findings provide a reference for studying wetland landscapes in the Tianjin Binhai New Area. In addition, the selection of the distance threshold in practical research can be adjusted according to specific research objectives and research level requirements.