[Objective] The differences in soil layer resistance to erosion under dry-wet cycles in typical erosion gullies in the black soil region of northeast China and the influence patterns of these differences on the development of gully erosion were analyzed, in order to clarify the mechanism of how dry-wet cycles act as an important driving factor for the rapid development of erosion gullies, and to provide a theoretical basis for the prevention and control of erosion gullies in the black soil region. [Methods] Soil samples were collected from gully sidewalls of cultivated land in the black soil region at depths of 0—30, 30—60 cm, and 60—90 cm. A laboratory-simulated dry-wet cycle experiment was conducted to determine erosion resistance indicators including soil basic physical properties, soil mechanical composition, water-stable aggregates(WSA), soil disintegration rate(SDR), and soil anti-scour coefficient(ANS). Differences and variation patterns in erosion resistance among the three soil layers were analyzed and compared. [Results] Dry-wet cycles had significant effects on WSA, SDR, ANS, and other indicators across all three soil layers. After one cycle, percentage of aggregate destruction(PAD) in the three layers decreased by 0.51%, 8.64% and 1.29%, respectively. In contrast, ANS in the 0—30, 30—60 cm and 60—90 cm layers increased by 171.03, 287.84 L/g and 5.59 L/g, respectively. After five cycles, SDR in the 0—30 cm layer showed the largest increase of 72.29 g/s, PAD in the 30—60 cm layer increased by 7.23%, and SDR in the 60—90 cm layer reached its minimum, decreasing by 6.1 g/s. After eight cycles, PAD increased by 4.315% and 7.78% in the 0—30 cm and 30—60 cm layers, respectively. Overall, WSA in the 0—30 cm layer decreased and SDR increased markedly with increasing cycle number, although the relatively large proportion of particles > 2 mm and high soil porosity provided it with strong resistance to scouring. The 30—60 cm layer exhibited improved water stability after one cycle, indicating temporary structural enhancement. However, structural degradation and reduced anti-scour resistance occurred after 5—8 cycles, although resistance to disintegration remained higher than the initial state. The 60—90 cm layer showed poor water stability, high SDR, and weak anti-scour capacity, and its structure was difficult to recover once damaged. [Conclusion] Dry-wet cycles intensify the vertical differentiation of erosion resistance along gully sidewalls, with the surface layer remaining relatively stable, the middle layer exhibiting pronounced fluctuations, and the deep layer being the most vulnerable. This process promotes gully wall collapse and accelerates gully expansion, providing important implications for soil and water conservation and gully erosion control in black soil regions. Management strategies should therefore emphasize structural improvement and enhancement of anti-scour capacity, particularly in the middle and lower soil layers.