Abstract: The feasible accessibility of external transportation hub in urban area was studied in this paper. The definition of accessibility for transportation hub was represented based on the analysis and summary of the previous research and the existing problems. The accessibility of urban external transportation hub was described by the indicators including travel time, cost and comfort. The accessibility was quantified by the time costs, economic cost and fatigue of travelers. According to the disadvantages of current hub accessibility model, an improved accessibility calculation model based on dimensionless method and disaggregate analysis was proposed. The validation and feasibility of the new model were verified by a specific case study.