In the site selection of pedestrian bridge, the scientific prediction of pedestrian flow and vehicle flow is the key to determine the site selection and scale of pedestrian bridge. According to the unique characteristics of the pedestrian bridge site selection project in the planned road, the principle of site selection of pedestrian bridge is discussed. Combined with the Jinjiang Pedestrian Bridge Project, the application of TransCAD in pedestrian traffic prediction is introduced, and the HCM evaluation method is introduced to grade and evaluate the pedestrian service level. The research shows that the prediction results can provide the scientific basis for the site selection and scale demonstration of pedestrian bridges, and the OD inverse method, HCM evaluation method and double-constraint model can also provide the reference for the design of site selection projects of similar pedestrian bridges.