The pore throat structure is complex and the pore throat radius is small in low permeability reservoirs. The fluid flow in the low permeability reservoir shows obvious non-linear percolation characteristics,and there is a certain start-up pressure gradient. The thickness variation characteristics of boundary layer within the capillary is analyzed. Based on the boundary-layer theory of fluid and capillary model of the low permeability reservoir,a new non-linear percolation model in the low-permeability reservoir is established. The new model is verified by the flow experiments of the low-permeability cores,and the radial non-linear percolation model of a single well is summarized. Based on the differences of different percolation regions,the differential development strategies of the low permeability reservoirs are determined. The theoretical analysis shows that the non-linear percolation model of the low permeability reservoir based on boundary-layer theory can accurately describe the flow characteristics of fluid in the low permeability reservoir. The percolation area of the low permeability reservoir can be divided into fast flow area,slowly flow area and detention area. The difference between the boundary of fast flow zone and that of slowly flow zone is different,and the technical approach of enhancing oil recovery is different for different types of low permeability reservoirs. For the general low permeability reservoirs,the effective displacement pressure gradient can be established by well-pattern matching,which promotes the boundary docking of slowly flow zones between injection and production wells and improves sweep coefficient of reservoirs. The slowly flow area can be transformed into fast flow area through reservoir stimulation and other measures in the ultra-low permeability reservoirs. By optimizing well spacing,dead oil areas can be reduced and the producing degree of reservoir reserves can be increased in the tight reservoirs.