Abstract. Architectural heritage holds significant historical and cultural value. However, it faces substantial risks of deterioration stemming from natural aging and human activities. Traditional methods rely on manual surveys or ground-based measurements, which are time-consuming and labor-intensive, making it challenging to meet the demand for large-scale stability assessments of architectural heritage. In this study, we designed a methodology based on the analysis of differential deformation and angular distortion of buildings using InSAR line-of-sight (LOS) displacements. Then, the stability of buildings is categorized into three groups: stable, moderate, and unstable, using these stability indicators. A total of 74 TerraSAR-X images acquired from August 2017 to November 2019 in ascending orbit were used to monitor the Jianchuan Ancient Town, which has a history of over 650 years. Our evaluation reveals that among the 1891 architectures in Jianchuan Ancient Town, 1191 are rated as stable, 696 as moderate, and 4 as unstable. Time-series results indicate that one of the four unstable buildings exhibited a severe accelerating trend that requires attention. In conclusion, this methodology can enhance the capability to assess the stability of large-scale architectural heritages.