After screening the typical relative permeability curves of thin and poor reservoirs in Xing 6 area,the flow coefficient is used as the weight coefficient to compound the normalized curves of single layer, and the composite relative permeability curves are obtained. The study of composite relative permeability curve shows that thin and poor reservoirs in Xing 6 area have the characteristics of residual oil saturation, low irreducible water saturation, low oil displacement efficiency and narrow common permeability area. According to the relative permeability curve, the water cut and recovery degree are calculated. The results show that the relationship curve between water cut and recovery degree can be divided into two types: convex and S. By studying the relationship curves between displacement efficiency and permeability, crude oil viscosity and displacement pressure gradient of thin and poor reservoirs in Xing6 area, it can be seen that displacement efficiency increases with the increase of permeability and displacement pressure gradient, and decreases with the increase of formation crude oil viscosity. The correlation analysis between oil displacement efficiency and micro⁃pore parameters shows that the correlation coefficient between pore radius and oil displacement efficiency is the smallest, only 0.090. The correlation coefficient between displacement efficiency and throat radius is 0.437. The results show that the effect of pore radius on oil displacement efficiency is small in micro pore structure parameters, and the effect of throat radius and pore throat ratio on oil displacement efficiency is greater.