Abstract: Based on the integrated analysis of properties of the various urban intersections,the authors theoretically improve the traditional signal timing method,build the double-layer model under bus priority condition targeting at the intersections equipped with bus lanes,and carry on the quota calculation to this model using the genetic algorithm.The experiment results of the VISSIM simulation indicate better performances of the proposed model.Compared with the traditional timing method,the model not only decreases the average delay for both per passenger at the intersection and bus vehicles' running in the lanes,but also realizes the bus priority with causing no impairment to other vehicles' efficiency as well as guaranteeing the traffic at the intersection running smoothly.