In order to accurately layout the city cluster freight hub center, it is necessary to grasp the freight supply situation of each county in the city cluster; this paper puts forward a freight supply method based on network freight data and the shortest path algorithm in the county area of the city cluster. Firstly, the network freight data are cleaned and screened; secondly, the shortest path algorithm in Arcgis and the traffic resistance model are used to carry out the traffic accessibility analysis; thirdly, the traffic volume data in the network freight data are calculated as the impedance in the traffic resistance model. Finally, the Beijing-Tianjin-Hebei city cluster is used as an example to calculate the city cluster county accessibility. The experimental results show that it is consistent with the current situation of freight transport development in the Beijing-Tianjin-Hebei city cluster, which, side by side, proves the feasibility of the method.