Abstract: In the process of batch transportation in products pipelines, batch interface exists between different kinds of oil products. Water hammer wave speed in different sections of the pipeline is different for the oil products of different batches are different in density and bulk modulus. Furthermore, various conditions of hydraulic disturbances occur during the operation. And as a result, the hydraulic laws are complicated in the process of batch transportation in pipelines. Based on the characteristics of transient simulation, the hydraulic model of products pipelines which takes the batch interface into account was established by using the commonly used interval interpolation method and forward (backward) time interpolation method. Then, the forms, key points and boundary conditions of grid division were analyzed in detail. And finally, a new time interpolation algorithm based on characteristic method was proposed to solve the transient simulation of batch transportation in products pipeline. In this algorithm, the interval interpolation steps of commonly used characteristic method are omitted, so the calculation is simplified greatly. It can provide technical support for the scheme designing of batch transportation in products pipelines.