Abstract: The reconstruction project of Provincial Road 434 (Yulin Palace to Moxi) is located in junction belt between Qinghai-Tibet plateau and Sichuan basin, along with the route famous for natural scenery, fragile ecological environment and prominent geological diseases. For this reason, environment protection in the plan and design of route and position is of primary importance. The combination of the original road and off-line new construction, the cutting of old curves to straight line, newly-built bridges and supporting structures, spiral route development and other ways have been applied in this project to avoid steep slopes, mountains, rivers, and the mudslide ditches, so as to protect the ecological environment. After the completion of the project, there appears outstanding landscape feature and beautiful three-dimensional stretching line.