Aiming at the problems existed in public buildings, such as high energy consumption, heavy pollution and inefficient management, a novel global optimization technique was presented, named SGB (Smart Green Building) technique, in which wire and wireless hybrid sensor network is used to realize operating data monitor of the building. At the same time, the collected data is divided into information flow, energy flow, material flow and people flow, and is processed stratified, so as to achieve the existing buildings reform of energy saving, emission reduction and efficient management, to meet the requirement of green and intelligent. The critical factor of the technique is to deal with the operating public building as an entirety, and do the system-level optimization.