Landslides generally cause more damage than first predicted. Currently, many methods are available for monitoring landslides occurrence. Conventional methods are mainly based on single-point monitoring, which omits the aspect of variation in large-scale landslides. Due to the development of radar satellites, the differential interferometric synthetic aperture radar technique has been widely used for landslide monitoring. In this study, an experimental region in the Wudongde Hydropower Station reservoir area was studied using archived spaceborne synthetic aperture radar (SAR) data collected over many years. As the permanent scatterer interferometric SAR (PS-InSAR) technique is an advanced technology, it could be suitably used to overcome the time discontinuity in long time series. However, the accuracy of date processing obtained using the PS-InSAR technique is lower than that obtained using the single-point monitoring method. The monitoring results of the PS-InSAR technique only demonstrate the moving trend of landslides and do not present the actual displacement. The Advanced Land Observation Satellite and a high-precision total station were used for long-term landslide monitoring of the Jinpingzi landslide at the Wudongde Hydropower Station reservoir area. Based on a relationship analysis between the data obtained using the PS-InSAR technique and the total station, a revised method was proposed to reduce the errors in the PS-InSAR monitoring results. The method can not only enhance the monitoring precision of the PS-InSAR technology but also achieve long-term monitoring of landslide displacement from a bird’s-eye view.