A smart building management system manages a building for providing smart analyses and strategies. The management system connects with plural hardware devices in the building and receives the data and statuses replied by the hardware devices, and further analyzes the maintenance statuses and energy consumption statuses of the hardware devices. Then the management system gathers the statistics of the total energy consumption statuses of the building according to the energy consumption statuses of the hardware devices. The management system receives the requests of users through a graphic user interface. The management system plans an energy-saving strategy based on the maintenance statuses of the hardware devices and the requests of users, and adjusts the hardware devices depending on the energy-saving strategy. Therefore, the total energy consumption statuses of the building meet an energy-saving target set by users in advance.