Abstract: To optimize congestion pricing policy, congestion pricing function was established by using congestion level as the decision variable.Then, game models of traffic mode choice were built with and without congestion pricing policy respectively.The model analysis shows that it is necessary to implement congestion pricing policy.It is concluded that when congestion pricing rate is real-time changed, marginal revenue will present inverted “U”type with bus return ratio increasing, and optimal bus return ratio is existed.