The interlayer taken as architecture interface inside channel sand body was thin. There were differences in lithology and shielding of interlayer which shielded the flow of fluid and influenced the distribution of remaining oil. This paper took North Second Area of Daqing Oilfield as an example. The core of sealed coring wells and vertical high resolution microelectrode logging data were used in this study. The lithology of interlayer was analyzed by using the intersection of amplitude values, amplitude difference and the rate of return of well logging curves on the basis of core identification. The lowest value of RMN (resistivity of micro normal) and the rate of return of RMG (resistivity of micro gradient) were selected as criteria of interlayer lithology identification. The identification rate of interlayer lithology was up to 82%.Taking oil bearing interlayer as basis, the interlayer was divided into three types: complete block interlayer, strong limit interlayer and weak limit interlayer. Considering the relationship of lithology and shielding, the lithologic interpretation method of the interlayer shielding inside channel sand body was established. The identification rate of interlayer shielding was up to 72%. Therefore, this paper laid the foundations for the deep study that the architecture influenced the displacement path of injection and the distribution of remaining oil in underground channel sand body.