Different from other rock types, loess rock has obvious characteristics of collapsibility after encountering water, which in turn triggers macroscopic geological disasters. The occurrence of these phenomena is closely related to the internal minerals, pore distribution and permeability anisotropy of the loess. Therefore, further study the internal structure of loess rock has important scientific significance for analyzing the causes of collapsibility characteristics of loess, and can provide a way to explore the research ideas of the relationship between mineral shape and porosity and permeability in addition to loess lithology. For these reasons . loessite samples of A region are selected to analyze the components and shape of mineral by using micro-CT images in the paper, the pore network distribution of loess rocks is simulated, and the fluid motion form is described based on Navier-Stokes equation and Darcy seepage flow formula. Twelve pore subvolumes (360μm×360μm×360μm) what were extracted from the segmented pores are used to analyze penetrating quality in different orientation. The results prove that the shapes of different minerals such as quartz and feldspar, heavy minerals and mica in loessite vary greatly, there is a good correspondence between long axis and psephicity, volume components; The distribution regularity of all kinds of minerals is not strong in loess rocks, the pore distribution is very scattered, the connection mode between pore and throat varies greatly, and the pore space distribution is highly heterogeneous; Compared with quartz, feldspar and heavy minerals, mica, due to its shape characteristics, greatly affects the formation and later occurrence of pores in loess rocks, and indirectly plays a crucial role in the generation of anisotropy of permeability.