With the acceleration of global urbanization, land use change and climate change have become key elements affecting regional ecology and sustainable development. Focusing on Tianjin, this study explored the spatial and temporal evolution patterns of land use change and climate change on vegetation cover and their driving mechanisms from 2000 to 2020. The impacts of land use and climate change on NDVI were quantitatively assessed by remote sensing images and meteorological data, combined with the land use transfer matrix and statistical analysis methods. The results show that during the period of 2000-2020, the land use change in Tianjin is remarkable, the rapid expansion of building land becomes the main driving force, the area of forest land and grassland decreases first and then increases, and the change of unused land shows a stage characteristic. The contribution of land use change to vegetation cover change is higher than that of climate change, and its influence increases with time. The overall trend of NDVI increases and then decreases, which is closely related to land use change and ecological protection policies. In terms of climate change, the synergistic effect of temperature and precipitation showed significant seasonal differences, with the highest correlation between NDVI and temperature in autumn and a negative correlation between precipitation and NDVI in winter. The study reveals the complex influence mechanisms of land use and climate change on vegetation cover in Tianjin, providing a scientific basis for ecological protection and land resource management in the process of urbanization, as well as a reference for sustainable development in other urbanized areas.