Building automation refers to the electrical equipment in buildings, such as elevators, water pumps, fans, air conditioners, etc. its main working nature is strong electric drive. Usually, these devices are in an open working state, that is, they do not form a closed loop. As long as the power is turned on, the equipment is working. As for the working state, process, energy consumption, etc., data cannot be obtained online in time, let alone rational use and energy conservation. Now, building automation is to monitor the above electrical equipment online, detect the working state of the equipment by setting corresponding sensors, travel switches, photoelectric controls, etc., and return to the central computer of the control room through the line. The computer obtains the analysis results, and then returns to the equipment terminal for mediation.