Abstract: Loess subsurface-erosion refers to the erosion, transport and subsidence of loess caused by surface water infiltration along the dominant seepage channels such as loess macropore joints and fissures. Due to the characteristics of water sensitivity, structural surface development, dominant seepage, etc., loess subsurface-erosion has developed extensively in the loess area, and loess subsurface-erosion has a significant disaster effect, making the mechanism and prevention of loess disasters induced by erosion more complicated. This article first combed the basic concepts of loess subsurface-erosion, based on summarizing the main controlling factors of loess subsurface-erosion, expounded the formation mechanism of loess subsurface-erosion, and expanded the basic connotation of loess subsurface-erosion disaster effect. Finally, according to the current research status of loess submergence, a brief prospect is made for the future research of loess subsurface-erosion, and it is pointed out that more attention should be paid to the research on the key linking role of loess subsurface erosion in the loess disaster chain. This article focuses on the preliminary thinking of several problems in the study of loess subsurface-erosion, and aims to provide scientific suggestions for the subsequent study of loess subsurface-erosion hazard effects.