Abstract: Self-priming pumps are used widely in oil ship loading, stripping, train loading, fueling for planes and tanks. Because the medium transported in pipeline is inconsistent with the working environment, it brings a lot of difficulties for users to select pumps. Some pumps even can't work properly. In this case, this article describes the specifications of self-priming pumps and analyzes the relation of self-priming property in the process of storage. On the basis of experiment and statistics, it proves calculating formula of self-priming property for normal products and stipulates maxim installation allowance of horizontal pipeline length and vertical pipeline height. It also stipulates more detailed priming height and time of normal oil products for different type centrifugal pump and vertical pipeline at different length or height which provides users a foundation for selecting pumps and its application.