Abstract: Supply shortage often occurs during the peak period of gas consumption, which not only decreases the benefits of gas companies, but also reduces the satisfaction of customers. In order to speed up the coordinated development of gas production, supply, storage and marketing, research was performed based on the downstream gas supply shortage resulted from the upstream supplier accident in the gas supply chain, with the influence of different pipeline mechanism considered, to meet the constraints of node capacity, station balance, user demand, and the balance of supply and demand. Meanwhile, two optimization models were established for the purpose of maximizing the benefit and minimizing the shortage index of natural gas, and then CPLEX was used for optimization to obtain the solutions of the mixed integer linear programming model. The gas supply strategies under different pipeline mechanisms were obtained based on a natural gas supply chain, and the accuracy of the new optimization models was verified. The optimized gas purchase and sales decision has guiding significance, and is capable of providing pre-warning and emergency plan for the reasonable gas distribution and supply in the peak period.