Geological disasters caused by surface deformation are common, especially in urban areas, which seriously hinders the sustainable development of urbanization. In order to evaluate the risk of geological disasters caused by urban surface deformation, monitoring and analysis with high temporal and spatial resolution becomes particularly important. Based on Sentinel-1A satellite images from January 2019 to January 2021, SBAS InSAR and PS InSAR technology is used to obtain the time series of surface deformation in Nanchang, and wavelet periodic analysis and grey correlation analysis combined to evaluate the correlation between deformation area and climate environment. The research shows that the central urban area of Nanchang is affected by urban construction and clay layers, showing a large-scale subsidence signal; the agro-ecological areas in the southeast show uplift signals due to groundwater replenishment. Periodic analysis further shows that the surface deformation of Nanchang is affected by the change of precipitation. Combined with external data, this study examines the possibility of subsidence disasters of subway lines in areas with large deformation from multiple perspectives, thus providing reference for disaster prevention and reduction.