Considering the conflicts between vehicles and between vehicle and pedestrian at the intersection with signal control, the microscopic traffic simulation model of the intersection is constructed under the Discrete Event System Specification (DEVS). By calibrating simulation parameters with observation data of a typical intersection in a city, the simulation results are compared with the calculated traffic capacity according to the "Specification for Urban Road Engineering", and the model is verified. On this basis, first, the influence of the amount of left-turn ratio on the traffic capacity of intersection is analyzed by the simulation. Then, an intelligent green ratio control strategy is designed based on the number of vehicles waiting to cross the intersection in each direction. The simulation results show that, the capacity increases first and then decreases with the increase of the ratio of left-turn vehicles; and the intelligent green ratio control can significantly improve the traffic capacity of intersection and significantly reduce the average approach road delay time. These prove that the simulation model can truly simulate the interaction of various intersection factors, and is easy to expand and universalize, which can be applied to the study of other intelligent traffic problems.