Soil degradation is an essential environmental problem that threatens agricultural productivity and sustainability in the typical black soil region in northeast China. Assessing the degradation status and risks of sloping cropland is necessary to restore and reconstruct degraded soil. This study aimed to map soil degradation status based on a newly developed soil degradation index (SDI) and assess the uncertainty associated with degradation risk mapping using Ordinary Kriging and Sequential Gaussian simulation (SGS). The results showed that SDI ranged from 0.013 to 0.864, with a mean value of 0.445. The realization with 200 times by SGS was the best, with an increasing pattern of SDI from north to south in the study area. Mildly degraded and moderately degraded sloping cropland accounted for 35.3% and 52.4% of the total area of sloping cropland, respectively. High-risk areas were mainly distributed in the Greater Xingan Mountains and Changbai Mountains to the Songnen Plain. Proactive measures are necessary to control and mitigate further degradation by developing soil management and weakening the interaction between slope gradient and ridge-slope angle. The developed risk assessment maps provide baseline information for regional sustainable development.