As the Daqing crude oil's higher viscosity impacts the quantity of mixed oil, during the process of crude oil batch transportation between the Daqing and Russia, the control equation of mixed oil was established based on the sequence mixed oil conveying mechanism. Using the finite volume method computes batch transportation of different flow velocity through CFD software. And the reason that the lower viscosity of the Daqing oil, the lower quantity of mixed oil under different flow patterns was analyzed. And the feasible suggestion was that was adding adequate amount of viscosity breaker chemical or moderate diesel oil into the Daqing crude oil nearby the interface in order to decrease the quality of mixed oil in the process of transportation.