Abstract: When designing the external road structure of Huangzangsi water conservancy project, according to the external road use function and the main project construction features, three different schemes of clay-bound macadam pavement, cement concrete pavement and asphalt concrete pavement are selected. Compared with other schemes in terms of project investment, construction speed, reconstruction and maintenance, the pavement structure type of forever-temporary combination is recommended.That is, using the clay-bound macadam pavement during the construction period, using the asphalt concrete pavement during the operation period.