Optimizing the design of mountain roads can improve the service life of highways, reduce the maintenance costs in the later period, and promote the economic development of mountain areas. Based on the actual situation and data analysis of mountain expressway lines, this paper summarizes the natural ecological environment conditions and topographic and geomorphic features involved in the geological survey report, and discusses and studies the highway design according to the natural environment characteristics along the line. On the premise of ensuring the safety and reliability of the project, the ecological scheme is adopted to apply the optimal design scheme of mountain expressway, Under the condition that the base is stable and the landscape along the line is not strongly affected, the high dam scheme can be selected by increasing the base compactness, reducing waste and waste utilization, so as to reduce the project cost.