For reduce the carbon emissions of grain transportation, improve ment the efficiency of grain transportation and ensurance the safety of grain transportation, this paper constructed a location-routing optimization model of grain transshipment hub driven by low carbon according to the perspective of quantitative analysis. An improved genetic algorithm was designed to solve the model, which could improve and optimize the layout of China's existing grain transportation network. Finally, some provincial capital cities on the key line of grain logistics were selected for analysis and verification. The results showed that The model and algorithm of hub node sitting-route optimization in hub-spoke multimodal transport network could reduce the total grain transportation cost by 13.87%. Carbon emissions were reduced by 11.70%, and the average transfer saturation of hubs was increased by 9.66%. This method was suitable for the actual grain transportation process, and can realize the low-carbon and efficient transportation of grain, which could provide reference for the location and path planning of Chinese grain transport hub under low-carbon drive.