Abstract: Starting from N-S equations of fluid mechanics, the flow mathematical model of two-phase flow in pipe is established. On the basis of fluid mechanics analysis on the interaction of two-phase stratified laminar flow in pipe, a system of mathematical equations to completely describe the stratified laminar flow in pipe is obtained. By means of the numerical solution to deal with the systematical equations, the important flow laws to actual engineering are obtained. Applying the laws, the high-effectively transporting of viscous fluid can realize.