<p>On February 22nd, 2023, a catastrophic landslide occurred on the northern slope of the Xinjing open-pit coal mine in western China, resulting in 53 fatalities and 6 injuries. Although synthetic aperture radar interferometry (InSAR) has been extensively utilized to monitor pre-failure deformation for such event, previous studies often overlook the topographic artifacts in interferograms caused by significant elevation changes—an intrinsic feature of open-pit mines. These artifacts degrade deformation mapping accuracy, obscuring accurate characterization of pre-disaster deformation processes. This study employed full scatterer (FS) InSAR technology to derive precise ground deformation measurements across the entire Xinjing coal mine with an ultrahigh measurement density of 4,710 points/km², via a dual-scale temporal low-pass filter (DTLF) to separate temporal high-frequency DEM elevation errors from low-frequency deformation signals. Time-series deformation analysis demonstrated that precursor deformation at the base of the 2023 landslide body accelerated markedly post-January 2022, serving as an early warning signal. This failure mechanism was validated in two earlier slope failures, one on the northern slope and another on the southern slope. Further analysis of multi-temporal satellite optical images and DEMs revealed that, despite official open-pit mining authorization in August 2012, large-scale mining had already occurred across 0.48 km² with a maximum depth of 39 m, and from 2012 to 2015 the mine developed rapidly, with a mining depth of 156&#xa0;m. This study demonstrates that spaceborne InSAR technique can not only map ground deformation in low-coherence open-pit mines with substantial surface alterations but also clearly trace pre-failure acceleration patterns—critical insights for slope stability monitoring and the development of safety protocols in open-pit mining operations.</p>