The composition and structure of lacustrine basins in arkose，lithic sandstone，and quartz sandstone are commonly influenced by clay minerals. Reservoir pore size is generally affected by these minerals. Rock mineral components were classified through diagenesis research. Scanning electron microscopy，X-ray diffraction，and constant-rate mercury injection were employed for analysis. The evolution of porosity and permeability in tight sandstone was quantitatively evaluated. The results show that Chang 4+5 oil layer delta front subfacies contain six sedimentary microfacies. Fine-grained lithic arkose and fine-grained arkose are identified as the main rock types. A minor amount of fine-grained feldspathic lithic sandstone is developed. The cements consist of siliceous material，ferrocalcite，kaolinite，chlorite，and illite pores are filled with chlorite as matrix. Reservoir damage is caused by chlorite in this form. However，a constructive effect is provided by chlorite coatings on pore surfaces. The reservoir is damaged by illite. In contrast，a constructive role is played by kaolinite. The research findings provide a theoretical basis for sweet spot prediction in the Ordos Basin and similar highly heterogeneous reservoirs.