The theory research of engineering management in China always follows the idea of western project management knowledge system. There is lack of the logic and structured theory system with local characteristics, which needs to be closely analyzed and studied. This paper establishes the engineering management theory system conceptual model,which is the "tree" model,according to the scientific constructing methods abide by the logic process from abstract to concrete. The "tree" model organically links the basic theory,main theory and applied theory, vividly embodies the interactive relationship between theory research and practice,theory development and environment, and has the characteristic of opening,moving and developing.