As the estimating of natural gas consumption can provide a better guidance target to gas production and market development ,its accuracy is playing an extremely important role in both the reasonable programming of oil and gas field development management and the promotion of economic benefits. This article builds a mathematical model of combinatorial optimization based on the natural gas consumption data of China, and solves it then by means of MATLAB .Compared with the actual value, the deviation of the combinatorial optimization worked out less than that in the single calculating method. When applied to the real production, this model can provide theoretical evidence to the programming of oil and gas development management and the adjustment of development project as well.