Abstract: Capillary pressure is not only a function of saturation but also a function of saturation change rate for oil-water two-phase flow.The dynamic capillary pressure is related to viscosity,permeability and displacement rate.Through the establishment of mathematical model for dynamic capillary pressure under oil-water two-phase flow,by using the numerical simulation software,the dynamic capillary pressure effect on development dynamic status in low permeability reservoir has been analyzed,and the relationship between dynamic capillary pressure and the reservoir heterogeneity has also been discussed.The results indicate the dynamic capillary pressure will accelerate the increase of water cut and decrease of oil rate,and heterogeneity will exacerbate the impact of dynamic capillary pressure.