Abstract: The surface gathering system in an oilfield is complex. Practically, its layout is commonly designed on the basis of human experience but rarely with optimization methods. In this situation, according to the gathering process of the system and taking the minimum investment in pipeline network layout as an objective function, optimization modeling analysis is conducted for four sub-modules, i.e. optimal partitioning for well group, determination of optimal position for metering station, network layout optimization and pipe diameter optimization. The case study shows that the model established is feasible in solving specific problems. It can effectively address four aspects above and thereby realize the layout optimization of the whole surface gathering system in oilfield.