For people improving the energy-saving performances of buildings, the applications of information communication, computer network, automation control etc. are the current building energy-saving technologies. They form with a serial of technique measures for buildings with energy management systems running implementation and intelligent monitoring. This paper introduces and analyses the information technology in building energy-saving. For building energy-saving on the demand for intelligent building energy monitoring, this paper proposed a system framework of Building Energy Monitoring and Analysis System based on the Internet of things, which has some enlightening in building energy consumption further to achieve real-time monitoring and control, and improve the energy-saving of intelligent building.