[Objective] The impacts of straw mulching technology on the gully erosion in black soil area were evaluated in order to provide reference for vegetation restoration and soil erosion prevention.[Methods] Field experiments were conducted to observe the variations in soil hydrothermal conditions, alfalfa growth, and soil as well as water loss in two slope aspects of gully banks under the presence and absence of straw mulch.[Results] ① Straw mulching was observed to significantly improve the soil water and heat conditions in the gully. Straw mulching on the shady and sunny slopes increased the soil moisture by 1.8%-6.8% and 1.1%-4.0%, respectively, and reduced the soil temperature at 14:00 by 0.6-3.1℃ and 0.9-3.6℃, respectively. ② Further, the straw mulching evidently improved the growth and biomass accumulation of alfalfa in two slope aspects of the gully banks, which was conducive to the vegetation restoration of gully banks. ③ Straw mulch could also effectively reduce soil erosion on the gully banks. The annual average runoff and sediments reduction rates were 57.34% and 67.60%, respectively.[Conclusion] The results obtained indicate that straw mulching is an effective measure for the control of gully erosion; consequently, the promotion of this technology will facilitate the reduction in the soil and water loss in the black soil area, which will ensure the food security of the country.