通过对传统公路选线方法的特点进行分析，提出多目标非线性优化方法，即利用方案网络图法构造路线的备选方案，建立符合公路选线特点的多目标非线性的优化模型，从而找到最优路线方案。通过对优化模型的分析，探讨优化模型的求解方法，提出约束法、分层序列法、评价函数法、逐步法等4种求解方法。对4种求解方法进行对比分析，结合公路选线影响因素众多的特点，认为约束法是解决优化问题的一种较为实用的方法。

According to the analysis of the characteristics about the traditional method of the highway route selection, the multiobjective and nonlinear optimized model was put forward. The option of highway route was created by project network. The optimized model suited the highway route selection with multiobjective and nonlinear was established and the best route would be reached by solution. Four solutions such as the constraining solution, the hierarchical sequence solution, the evaluation function solution and step by step solution were put forward by analyzing and resolving the optimized model. After comparing four solutions and considering characteristics of highway route selection, the constraining solution was recommended as a more practical approach. In the end, an example was given to show how to construct the project network, how to establish the model, and how to seek the model’s refinement method.