In order to improve the traffic efficiency and reduce the vehicle conflict in the confluence area of freeway interchange, taking the vehicles in the confluence area of freeway interchange ramp as the research object, an optimization method of safe sight distance in the confluence area of freeway ramp based on game theory is put forward in this paper. By analyzing the driving behavior and running characteristics of drivers of main line and ramp vehicles in the confluence area, the profit function of the confluence process of main line and ramp vehicles is constructed and the Nash equilibrium state is solved with the maximum traffic efficiency as the control objective. The simulation software (VISSIM 4.3) is used to verify that the travel time of main line and ramp in confluence area is shortened by 5.26% and 17.65%, and the delay time is reduced by 17.65% and 32.88%, respectively. The results of vehicle trajectory analysis show that the number of rear-end collisions and lane-changing conflicts are reduced by 23.09% and 29.05%, respectively. It is concluded that the optimization of the viewing distance can effectively reduce the conflict in the confluence area of the interchange ramp.