Abstract: Under the conditions of given intersection space design and signal phases and with the restriction of traffic delays (level of service) of motor vehicles and non-motor vehicles, this paper presents an optimization model for the maximum motor vehicle traffic capacity using the traffic flow control theory. And the model is solved by a hybrid algorithm, which combines genetic algorithm with chaos optimization algorithm. The results of actual calcul ation indicate that the theory value and practice value of the optimization model are high. New ideas and methods are provided for the coordinate and optimal control of the traffic flows in signalized intersections.