Visualization technology has been extensive used in various fields which makes the information presented in a visual way. Visualization directly improves the cognitive efficiency of information, greatly reduces the complexity of data understanding, and breaks through the limitation of the traditional statistical analysis method. The automatic placement of nodes and edges in the network graph has been an important part of visualization research, and the automatic layout algorithm based on force directed graph is a kind of method in this kind of research. An abstract data model of the port transport network is built and the force directed model is improved and applied to port transportation network in this paper.