With the acceleration of urbanization, the existing county-scale national and provincial highways adjacent to urban suburbs increasingly fail to meet the growing demands of public transportation. The municipalization reconstruction of these highways is often an urgent necessity. Taking the Fuzhou Ganhong Road (Guanming - Yongfeng Ring III Connection) Upgrading and Reconstruction Project as an example, the existing road widening and reconstruction schemes for county-scale national and provincial highways are systematically expounded through the analysis on the road functional orientation, upper-level planning and traffic flow from the aspects of road cross-section layout, horizontal and vertical alignment design, key traffic node reconstruction schemes, and land access point sorting out and optimization. The design thoughts and key points for widening and upgrading the national and provincial highways are summarized, which can provide the insights and references for similar engineering projects.