Abstract: Distribution network planning is an important work of power grid companies. The complex structure of distribution network and numerous investment projects not only affect the production and operation of power grid companies,but also have a huge impact on people′s livelihood and national economy. At present,the investment decision-making of distribution network projects mainly depends on the experience and subjective identification of planners,which needs further objective and scientific decision-making methods.A life cycle economic benefit and social benefit evaluation model of distribution network project was established to evaluate and compare the investment benefit of distribution network project. A distribution network project optimization strategy based on the hierarchical sequence method was proposed,and three-level selection was carried out for the alternative item library,including rigid selection,benefit optimization and project by selection.The method proposed in this paper takes into account the importance of the project in policy and security and the economic and social benefits,which provides a scientific decision support method for distribution network project optimization.