Abstract: Considering the technical characteristics of products oil pipeline network, taking the pipeline system composed of pump, pipeline and valve as an investigated object, utilizing the basic law of hydraulic network to set up mathematic model, and calculating with network splitting algorithm, the pressure and flowrate in each branch pipe of the pipeline system within one transmission period can be obtained, thus the practical operation conditions will be predicted. The main idea is that the flowrate at any node is equal to the summation of the flowrate in all branch pipes related to it. Regarding the pipeline network as a tree, taking the sub-branch as a basic branch and through the tree branch plus the sub-branch to formulate the basic loop matrix to work out a basic branch and initial flowrate, the Jacob matrix and impedance matrix are calculated based on an independent loop matrix chosen arbitrarily from a given basic branch. The precision, speed and stability of the abovementioned model and algorithm are verified by a simple example. It might be the reference for the pipeline design and operation management.