Abstract: A traffic assignment and path optimization model in integrated freight transportation network was proposed within the perspective of green transportation to reduce energy consumption and carbon emissions in transportation area. Based on multi-commodity network flow theory, the model proposed in this paper set the binary decision variables which indicated whether the flow passed through the arcs or not, taken the service level as constraint conditions and the minimizing transportation costs and the carbon emissions cost as the goal. Finally, simulated data was used to validate the model by calling Cplex optimizer in Matlab language.