Abstract: Traditional models of gas pipeline optimization usually have many design variables and lots of constraint conditions which are very complicated. Consequently the speedy of optimization is quite slow and the corresponding optimized solutions are not satisfactory. This article presents a new model, in which the design variables and the constraints conditions are much fewer and much simpler. The model makes optimizing process speedy and an improved optimization algorithm is also presented. The global optimization solution can be reached with the algorithm and an example shows that the model and the algorithm are very effective.