Based on the sedimentary facies research, using the thin sections, scanning electron microscope observations and physical property, the pore and diagenesis features are analyzed. The main pore types are secondary pores of feldspar, debris and carbonate cements in the Chang 6 of the Zhiluo Oilfield. The micro larynx is the main seepage passage. The diagenesis includes compaction, pressure solution, cementation, and dissolution. Reservoir is controlled by the sedimentary facies zone. Finally, it leads the characteristics of low porosity and low permeability in Chang 6 reservoir.