The essence of intelligent weak current engineering is to serve mechanical and electrical engineering, so that it can better reflect the functional needs of mechanical and electrical engineering services for buildings, so that its high-tech organic integration in the mechanical and electrical equipment system, to become a true intelligent building. The implementation of weak current engineering is closely related to mechanical and electrical engineering, and the essence of some systems is attached to the mechanical and electrical equipment system, in order to ensure the essence of the project must pay attention to the following aspects: If the construction project adopts the general contracting method, the weak current project is closely related to the mechanical and electrical engineering, especially BA, FA and air conditioning, electrical, water supply and drainage, elevator, diesel engine, etc., so the weak current main contractor is usually in the mechanical and electrical general contractor, which is conducive to the cooperation and coordination between each other. (1) The main engineering interface of weak current and mechanical and electrical engineering, as mentioned above, the weak current system is mainly related to the cold and heat source equipment in the air conditioning system, AHU, various types of exhaust fans, elevators, power distribution lighting systems, diesel engines, and so on. It is necessary to determine the engineering interface of weak current system and electromechanical equipment in design, equipment material, technical interface and construction in different stages of engineering implementation. ① In the order contract of mechanical and electrical equipment, it must be clear that the technical requirements of the weak current system for these equipment (technical performance parameters and technical interface requirements), the supply scope of equipment materials, the technical design interface and the construction interface. Cold and heat source equipment: start-stop control requirements and methods; Such as communication mode must be clear connection mode, communication protocol, data format, performance parameter transmission requirements, interface equipment and software interface. AHU equipment: frequency conversion control requirements. Elevator equipment: with CCTV, video and power cable, card reader interface, floor display and elevator landing requirements. Power distribution equipment: monitoring parameter requirements and data transmission mode and interface interface. Diesel engine equipment: monitoring parameter requirements and data transmission mode and interface. ② In the technical design stage in the process of BA and FA technical design, it is necessary to further clarify the details and requirements of the specific technical interface between the subsystems, and to determine in writing, according to the requirements of the monitoring table and linkage involving the secondary circuit design of the electrical control box. Chiller (cold source equipment), elevator, distribution equipment (high and low pressure cabinet), diesel engine, heat source equipment, air conditioning water system valves as the basis for the construction design of both sides, and equipment material supply and construction interface to be re-confirmed and modified. ③ In the construction design stage, both parties confirm their respective construction designs and confirm the above four interfaces again, so that the consistency of the contract, technical requirements and construction drawings is the basis for both parties to provide a detailed list of equipment hardware, while preventing omissions or inconsistent interfaces, and maintaining consistency from the drawings, that is, ensuring the correctness of the drawings and avoiding rework errors during construction. It is the basic guarantee for the normal commissioning of the system.