In view of the increasing water content in China's oil fields, foam has good pugging performance and flow redirection effect, and has broad application prospects. In this paper, the sealing characteristics of bubble redirection effect was studied, the fluid flow was investigated under the condition of different seal characteristics of foam, and effect of flow redirection and enhancing oil recovery was examined. The results show that the foam has good plugging performance, and can be effectively blocked under suitable conditions. The higher the back pressure, gas liquid ratio and core permeability are, the lower the injection speed is, the bigger the resistance factor and residual resistance factor of the foam are, the greater the plugging is. For non-homogeneous reservoirs with a permeability differential of 5.56, foam has effect of flow redirection and can plug the high permeability layer in core selectively. The subsequent injection of water into the low permeability layer will drive out the residual oil, and the bubble drive will increase the recovery rate by 28%.