This paper analyzes the pipe network system of oil-gas collection and transportation foroffshore oilfield development.A“0-1”integer linear programming model is constructed to optimize theinvestment of seabed pipe network.The mathematical model is solved by the spanning tree method ofgraph theory and network analysis.All spanning trees of a network graph compose all the feasible solu-tions of the mathematical model.The optimal solution of the model is the spanning tree with the minimumcost among all spanning trees.This method can be used to optimize the seabed pipe network system andgive a minimum cost plan for the development of offshore marginal oilfield groups. This paper analyzes the pipe network system of oil-gas collection and transportation for offshore oilfield development. A “0-1 ” integer linear programming model is constructed to optimize the investment of seabed pipe network. Mathematical model is solved by the spanning tree method ofgraph theory and network analysis.All spanning trees of a network graph compose all the feasible solu-tions of the mathematical model. The optimal solution of the model is the spanning tree with the minimumcost among all spanning trees. This method can be used to optimize the seabed pipe network system and provide a minimum cost plan for the development of offshore marginal oilfield groups.