The invention relates to an intelligent power supply system for a building, which comprises a signal data acquisition circuit, a signal data computing and judging circuit, an equipment operation circuit, a troubleshooting method circuit, a wireless alarm transmitting circuit and a wireless receiving circuit, wherein signal data is acquired from a power supply system of the building and respectively connected with the signal data computing and judging circuit and the wireless alarm transmitting circuit, the output of the signal data computing and judging circuit is respectively connected with the equipment operation circuit, the wireless alarm transmitting circuit and the troubleshooting method circuit, the output of the troubleshooting method circuit is connected with the wireless alarm transmitting circuit, the output of the equipment operation circuit is connected with the wireless alarm transmitting circuit, and the wireless receiving circuit is connected with the equipment operation circuit. The intelligent power supply system utilizes the computer technology, the monitoring technology, the control technology and the communication technology to develop a real-time state, data detection, protection and remote control system for distribution transformers, 10kV load switches and 400V power distribution systems, which can play an active role in promoting the development of intelligent power distribution.