Abstract: The classification of stakeholders is of great significance in the differential management of them. In order to study the quantitative classification method of stakeholders, this paper firstly proposed an innovative construction method for stakeholders'social network model based on superimposed behaviors, which allowed the relationship of stakeholders visualized. Secondly, the quantitative classification method about the influences of stakeholders was proposed, i. e. , the stakeholders were classified as the type of core and border. Combing with the life cycle of a project, above concepts were validated with a case of biogas engineering from Baibi Biogas Professional Cooperative. The results demonstrated that different stakeholders at the same stage of a life cycle belonged to the different types, and one stakeholder at the different stage of a life cycle also was in the different type. This advanced method fits in engineering practice, and owns great significance in implementing differential management of stakeholders as well as improving the efficiency of project management.