Abstract: As an important transportation hub in Beijing, the Beijing South Railway Station (BSRS) undertakes the task of collecting, distributing and transferring a large number of passengers from the railway, the metro and the public transit system. It is necessary to compute and evaluate the transit accessibility to improve the convenience for railway passengers transfer to the capital. In this paper, an accessibility calculation model of multi-mode public transport was constructed by the travel time of the ground bus, the metro and the feeder bus from the BSRS to the urban area. The accessible range in different travel time periods was drawn by ArcGIS software based on the investigating data and application programming interface (API) travelling data. The transit accessibility was analyzed combined with the urban terrain structure and the land use. Both the travel time and the transfer times in the public transit system were selected as indicators to evaluate the transit accessibility of BSRS. Results show that the accessibility range of public transport is affected by the trend of metro line network and the distribution of stations. The accessible area is affected by land use such as topography, park facilities, etc. The accessibility in different periods is related to the traffic condition of ground bus. The proposed method can lead to the operational efficiency improvement of the public transportation hub. Meanwhile, the evaluation results have guiding significance for the optimization of urban public transport network.