Considering the limitations of current approaches of traffic detection after the new traffic laws are introduced, an intelligent detection system of driver’s seat belts is proposed based on OpenCV in this paper. It is combined with the appliance of linear fitting method, straight line detection method and gray integral projection method. Thus, whether the drivers wear their seat belts or not can be analyzed and judged by the system from acquired images, which can ensure the road traffic security and the safety of drivers and help to increase the efficiency of the police. We can accurately distinguish the drivers’ violation and realize the intelligent transportation.