Debris flows triggered by ice avalanches (abbreviated as DFIs) are a common catastrophic hazard in alpine regions, and their flow regimes may vary with ice content. Previous studies have focused mainly on the deposition characteristics, mobility, and hazard assessments of DFIs; however, no systematic investigations have focused on the basal stress characteristics and erosion mechanisms. In this study, a series of flume experiments were conducted to investigate the effects of the ice content on the flow regime and stress of a DFI during erosion. The results revealed that the flow regime of the DFI changed from friction-dominated to viscous/collisionaldominated flows with increasing ice content. Ice clearly contributed to the increase in flow velocity during erosion, whereas the effects on flow depth, stress and pore pressure were not significant. The erosion rate of DFIs was found to be independent of the water content of the bed and related to flow infiltration. Erosion affected only the uppermost soil particles, which immediately became saturated once DFIs flowed over them. Therefore, the critical Shields number can be used to describe the resistance of an initial soil bed to erosion, as the surficial soil particles are saturated by infiltrated flow. The shear stress exerted by the DFI can be directly measured, and then the erosion rate can be obtained. A comparison between the measured and calculated erosion rates of the methods in this study, those of a single-phase erosion model, and those of a two-phase erosion model proved that the results of our study were appropriate for describing the erosive forces of the DFI.