Abstract: The function of modules of hydraulic computation and pump station design which are integrated in a CAD system developed for medium or-small-sized oil tank farm and filling station design is analyzed and set up in this paper. It is detailed to analyzed the workflow of hydraulic computation module which is favorable to data exchange, putting forward 4 kinds of design manners for pump station designing, i, e. design based on unit blocks, design based on pump station group, design based on typical technological process, design based on experience, which realize combination of high-efficiency and flexibility in pump station design.