Abstract: Introduction Topography in mountainous area is complex, the large-scale equipments for transportation are heavy and long, better economy is demanded for the construction of the transportation road, which leads to difficulty in road route design. Method Based on a practical engineering, considering the cost proportion of the project investment, the feature of the wind farm equipments and the performance of the transport vehicles, analyzed the basic principles of the road route selection, researched the common and limited minimum horizontal curve radius and the maximum longitudinal grade of the road. Result The technical indicator demand of the road route and the constraint of the environment shall be considered in the road design, the grade of longitudinal profile is mainly dominated and the limited index is commonly used. Conclusion In use of the special vehicles for the transportation, the common minimum horizontal curve radius of the road is 30.0 m, the limited minimum horizontal curve radius is 20.0 m; and the common maximum slope is 0.14, the limited maximum slope is 0.17, the results can be reference for wind farm transportation road design and construction.