基于系统工程的思想，通过分析高速公路社会经济效益产生的机制，建立了区域经济—公路交通发展系统动力学模型，以天津市津蓟高速公路为例，通过系统仿真误差检验，证实了该系统动力学模型的仿真效果较好、性能稳定。通过已建—未建高速公路系统仿真结果的有无对比，计算并预测出了津蓟高速公路2003—2013年各年的社会经济效益，从而实现了高速公路项目社会经济效益评价的定量化目标，为今后类似项目的开展提供了理论指导。

Based on the theory of system dynamics, the paper analyzes the mechanism of socio economic benefits of highway projects and establishes the system dynamic model of regional economic－public road transportation. Then taking Jinji highway project of Tianjin as an example, the error of system simulation tested and the system dynamic model built are verified to be quite stable, which have a high performance. Through the comparison of simulation results of Jinji highway being built or not, the paper simulates and predicts the socio economic benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio economic benefit of highway project is realized and it will provide the theory instructions for similar projects in the future.