The emergence of intelligent building engineering as an independent field from building electrical engineering is determined by its unique characteristics. The characteristics of intelligent building engineering can be summarized as follows. ① The important hallmark of intelligent buildings is the intelligent integrated system. It is an integration of multiple technologies and disciplines, involving electronic technology, communication technology, network technology, computer technology, automatic control technology, sensor technology, etc. The key to achieving system integration lies in solving the interconnection and interoperability issues between systems, which permeates the entire process of planning, design, construction, and management of intelligent buildings. With the development of science and technology, new technologies and systems will continue to enrich and join this field.