This study proposes a potential-based three-dimensional cellular automata model to describe the route choice behavior of pedestrians while evacuating terraced stands. The model takes into account the pedestrians’ states of sitting, standing, and moving, and the possible transitions on terraced stands. The proposed potential field algorithm reflects the influence on route choice behavior of heterogeneous heights, route distance, pedestrian congestion, and route capacity. Three parameters related to the pedestrians’ behaviors in the spaces with heterogeneous heights are then analyzed to demonstrate the ability of the model to reproduce pedestrian route choice behaviors on terraced stands. Finally, empirical data observed in a terraced stand of a stadium are applied for further validation. The results show that the proposed model performs consistently well with the observed data.