Problems in subway station operation mainly exist at the place with service facilities, in this paper, Anylogic is used to simulate the assemble capacity under different layout of facilities. Pedestrian density, flow rate, service times and maximum arriving rate are selected to be the evaluations. The Hongshan Square Station is select for case study, the simulation is within an hour, analyzing from pedestrian density distribution map, flow rate chart of key points, service times of critical facilities and the maximum passenger arriving rate values, get the result that the assemble capacity is poor under current conditions, and the improvement measures are put forward. With these recommendations, assemble capacity of this station is obviously improved. This method can provide valuable theoretic and practical insights into the management of the layout of facilities, therefore, the optimization of assemble capacity can further be achieved in metro station.