The paper selects the influencing factors of EPC project’s cost control,analyzes and constructs the model of EPC project’s cost control from the point of view of system engineering,and utilizes the integrating DEMATEL—ISM method to study the relationships between the influencing factors and their impacts on cost control. And it gets the multilevel structure model of the influencing factors of EPC project’s cost control. The results show that project construction management level, procurement system, procurement process and standards project content acceptance and project settlement basis are the direct impacting factors of EPC project’s cost control. The study provides a reference of EPC project’s enterprises to improve project management level,effectively control project cost and achieve project management objectives.