Abstract: Heilongjiang Province, endowed with fertile black soil resources, is a crucial commodity grain base in China. However, unsustainable farming practices have exacerbated soil erosion, posing long-term threats to agricultural productivity and ecological security. Contour farming, a preventive and effective slope erosion control technique, involves aligning cultivation paths along contour lines to minimize surface runoff velocity, reduce soil and water loss, and enhance soil moisture retention and land-use efficiency. This method has been widely adopted in major agricultural countries such as the United States and Brazil, and successfully demonstrated in China’s Yellow River Basin and the black soil region of Northeast China. Research on a 3° slope farmland in Northeast China's black soil region shows that contour farming reduces runoff by 95.3% and soil loss by 95.5% compared to downslope tillage. However, its implementation remains challenging in fragmented fields. Application cases from several farms affiliated to the Beidahuang Group demonstrate that contour farming exerts significant positive effects on soil, water, and crop productivity. Specifically, this farming practice can reduce soil erosion by more than 50%, enhance the uniformity of water distribution in farmland, increase soil moisture content by approximately 30%, and promote crop yields by around 9%. Further optimization and integration with complementary technologies will provide valuable theoretical and practical insights for sustainable agricultural development in Northeast China’s black soil region.