The invention discloses an intelligent building energy-saving system based on an Institute of Electrical and Electronics Engineers (IEEE) 1888 standard in the technical field of Internet of things. The system comprises a building energy consumption collecting unit, a bearing network and a management unit, wherein the building energy consumption collecting unit comprises a wireless sensor and a gateway, the wireless sensor is used for collecting the energy consumption information of an energy consumption device and sending the information to the gateway, the wireless sensor is also used for receiving control commands forwarded by the gateway and controlling the energy consumption device to work, the management unit comprises a database server, an application server, a switch, an integrated service platform and a client, the database server is used for storing the energy consumption information, the application server is used for analyzing the stored energy consumption information, generating control commands in accordance with analyzed results and transmitting control commands to the switch, and the energy consumption information and control commands use the protocol transmission based on the IEEE 1888 standard. The data center energy quality management and reasonable use are achieved and the energy efficiency is optimized.