Abstract: Through the analysis of network planning optimization method for highway construction, the qualitydurationcostoptimization model with the characteristics of network planning for highway construction was established. The multiobjective optimization method based on NSGAⅡ was put up. The method was GA that using nondominated sort about crowding distance and elitism strategy. Through chromosome coding based on process, the search space of solution was optimized. Through the roulette wheel selection, arithmetic crossover and mutation operation, the Pareto optimal solution collection, that could allow decisionmakers to choose, was got. At last, through engineering examples, this paper confirmed that the optimization method could solve the Pareto optimal solution collection from establishing the optimization model, using MATLAB 7.0 simulation program.