Abstract: With the development of large-scale active phased array radar technology, the requirements for the integration of array functions and the lightening and thinning of array structures are becoming more and more strict. It is difficult to meet the needs of project development only relying on increasing the integration of discrete network modules. Therefore, a new concept of multi-functional synthetic network layer structure (MFSS)is proposed. In this paper the principle and composition of the synthetic network layer are introduced. It iselaborated that MFSS is the complex structure integrating machine, electric and heat. And several key issues are proposed which should be researched in the design process.