According to the non-linear increasing characteristics of the container throughput of port, triple exponential smoothing forecasting model, grey system forecasting model and BP artificial neural network forecasting model are established respectively, Due to the limitations of each single forecasting model, this paper put forward the combined forecasting model based on the optimum principle of the minimal sum of the forecasting error absolute values, the weighting coefficients are derived by linear programming. Finally, a practical case is given.