Abstract: On basis of minelayer correlation,by comprehensively study of core facies,and geological logging facies and well log facies,this paper discusses that Axx fault block is mainly braided river delta sediment,sedimentary microfacies aremainly braided channel,distributary channel and sand sheet. The research of reservoir heterogeneity,sedimentary microfacies distribution,and oil layers distribution has shown that plane nonhomogeneity and high vadose zone developed by distribution of sedimentary facies as well as oil layers distri-bution is dual controlled by tectonics and sand body. The research on sedimentary microfacies guided the development of the study block.