The traditional "extensive" road design leads to disordered traffic operation, low efficiency, traffic congestion and frequent traffic accidents. The refined design of urban road traffic organization can not only guarantee the traffic operation, but also coordinate the relationship between natural and social environment along the road. Taking Pingliang road section of Lanzhou city as an example, the fine design is studied and evaluated by using VISSIM software. The study shows that fine design plays a positive role in improving traffic capacity, ensuring safety and improving efficiency.