Abstract: This paper proposes a crowd simulation model based on the potential field. First, the moving paths of pedestrians in the crowd are planned by solving the Harmonic Equation. Traditional Harmonic Equation solver suffers from the local optimum problem; as such we introduce a "virtual wall" to overcome it. Then, a dynamic potential layer is added to potential field for collision avoidance. It is shown that the additional potential layer can effectively prevent pedestrians from colliding with obstacles or other pedestrians even for large crowd in complex scenes. The experimental results show good simulation fidelity and real-time performance, which demonstrates that the model can well meet the requirement of crowd simulation.