Offset intersection commonly exists in city road intersections, the special geographical characteristics of which consists of two T-legged intersections tend to make the passing vehicles stop twice in very short distance, thus often leading to severe travel time delay and low traffic service level. It is accordingly very important to set up a proper traffic control method to raise the discharge efficiency of the offset intersection. Based on analysis of geographical characteristics and traffic characteristics of a specific kind of offset intersection, a new traffic control method is proposed in this paper. Simulation results show that the discharge efficiency of the offset intersection is improved and the average delay is significantly reduced. The setting up steps, advantages and limitations of the control method is also analyzed.