Nano-biochar with unique characteristics compared to common biochar has been confirmed to promote soil physical properties. Highly weathered soils in arid and semi-arid areas are characterized by low soil nutrients and high erosion potential. This study evaluated the influences of nano-biochar made from oak tree branches on the soil, water, and nutrient conservation on a sloping land of the Chinese Loess Plateau. Five nano biochar rates (0.0%, 0.1%, 0.5%, 0.7%, and 1.0% by mass, equal to 0 t/ha, 0.0263 t/ha, 0.131 t/ha, 0.184 t/ha, 0.268 t/ha) were applied in three bands with simulated rainfall plots (1.0 m in length, 1.0 m in width) with five different vegetation covers (bare, alfalfa, bean, Caragana microphylla, and corn). A simulated typical rainfall event of 90 mm h -1 was performed for all the treatments. Experimental results indicated that the initial runoff time was delayed with the increasing nano-biochar contents. Compared to the treatments with no biochar application, soil, water, and nutrient losses in runoff significantly decreased. The conservation effect of nano-biochar was the most significant in the alfalfa plot. Soil containing 0 7% nano-biochar (0.131 t/ha) with alfalfa planting mollusc. This study provides an effective method for soil water and nutrient conservation.