[Objective] The spatiotemporal distribution of abandoned farmland in the core black soil protection area of Jilin Province from 2000 to 2023 was analyzed, the main driving factors of farmland abandonment were clarified, and the soil and water conservation effects of abandoned farmland are evaluated, in order to provide a theoretical basis for remote sensing monitoring of abandoned farmland and research on soil and water conservation effects in similar regions. [Methods] Based on the Google Earth Engine（GEE） platform and Landsat long-term time-series imagery, this study integrated multidimensional characteristics and combined random forest with LandTrendr change detection method to map the spatiotemporal distribution of abandoned farmland in the study area. Additionally, the key driving factors were analyzed using the geodetector. Finally, a comprehensive evaluation of the soil and water conservation effects of abandoned farmland was conducted using a combination weighting method based on AHP-EM-product normalization. [Results] ① The RF-LT model achieved an overall accuracy greater than 85% and a Kappa coefficient of at least 0.8, indicating high classification accuracy and good overall performance.② The area of abandoned farmland initially increased and then experienced a fluctuating decline after peaking at 459 km² in 2013. Spatially, it first increased then decreased, and finally showed local increases, with relatively scattered distribution of abandoned farmland.③ Night-time light intensity, average parcel area, and elevation had high explanatory power for farmland abandonment, with q-values all exceeding 0.4. Furthermore, the interaction between slope and average parcel area was the most significant, with a q-value of 0.997.④ The comprehensive scores of soil and water conservation effects for abandoned farmland in the study area with abandonment durations of 5, 10, 15, 20, and over 20 years were 0.388 6, 0.477 3, 0.801 4, 0.604 4, and 0.443 8, respectively, showing an initial increase followed by a decrease. [Conclusion] The moderate abandonment within a certain period has a positive impact on soil and water conservation, specifically reflected in the improvement of ecological diversity and soil properties.